In our last installment we compared seven major websites to see Which Airfare Site is the Cheapest, but we all know that the cheapest of anything isn't always the best choice. You want to get the best price, but that test showed that often times several sites tied for the lowest. If you've tried more than one or two of these, you probably know that they are each structured differently and some are much easier to use than others.

So for this comparison, we'll look at the steps on each site for someone who knows exactly what they want before they begin the search. Sometimes shopping in a mall can be an enjoyable way to spend a day off, but there is a reason why many of us go to the corner mini-mart when we only want one item.

How we did this test
We took one simple itinerary and compared the entire process from the first screen until the final purchase confirmation screen. On a scale of 1 to 10 with 10 being the best, we assigned one score for each site's search experience, and another score for the process from when you choose your flight until the moment you buy the ticket. Remember, these scores are assuming you know when you want to fly, and that all you need at this point is the ticket.

The test trip: San Francisco to Seattle, leaving Friday between noon and 6:00 p.m., returning Sunday between noon and 6:00 p.m.

Let's compare…

Expedia
Searching – The flight search function worked simply and it easily found a good pair of flights, but it wasn't as simple to use as some of the others. (6 out of 10)

Buying – After selecting the flights, we had to go down a long and bewildering road of several screens packed with add-ons. It began by confusingly asking if we had a coupon code, which can lead some people to start scrambling to find one in another browser window, even though they are almost never available for cheap flights like these. We had to scroll past offers for inns, rental cars, a $15.00 "Flight Protection Plan" (seems like the airborne version of extended warranties on electronics). Also, we had to get through about a dozen other promotions that ranged from an interesting $6.00 carbon offsets thing to bizarre, expensive spa gift certificates (at 5% off!), with offers for roundtrip transportation to Vancouver, BC on either a bus or a clipper ship.

When we finally got to the credit card screen, we were asked for an account number to the ThankYou® Network with a promise that we'd get more information about that free rewards program after our ticket was confirmed. If the goal was just to buy a ticket, Expedia made it as difficult and confusing as possible. (2 out of 10)

Orbitz
Searching – The Orbitz search box allowed us to select a time range nearly identical to our goal; the results screen came up with an ideal roundtrip right on top. It allowed us to choose one or both of the departing and returning flights on the same screen, which is helpful. (8 out of 10)

Buying – The first confirmation screen tried to add an accommodation stay, but it did it with an impressive search tool built into the page. After confirming that we didn't want an accommodation at the bottom of that screen, another page of add-ons came up. At least they were sensible offers, with a “proceed” button near the top so we could skip scrolling through them altogether. The following page made us check a box refusing the $13.50 Ticket Protector, and then asked us if we wanted to select our seats before entering the credit card information. Avoiding all the attempts at up-selling wasn't difficult. The exact seat selection option was a plus. (6 out of 10)

Travelocity
Searching – We entered our dates and preferred times. Travelocity's search seems to be bundled with a pop-under ad that outsmarted our pop-up blocking software. The results page made us choose flights individually, but the relevant choices were at least near the top. (4 out of 10, two points deducted for that pop-under ad).

Buying – After the flights were chosen, we had to scroll past 10 accommodation offers on the following screen, which would have been slightly less annoying if four of them weren't located 90 miles north of Seattle in the small city of Bellingham. On the following screen we had to consider the Flight Protection for $15.95. With one more click, we entered our details, selected exact seats. Aside from the odd accommodation suggestion, Travelocity didn't send us too far astray. (5 out of 10)

Hotwire
Searching – Hotwire's search box didn't allow us to enter a preferred time of day, and then the results came only in roundtrip pairs with no obvious way of mixing and matching them. But a far bigger problem arose when we noticed that Hotwire completely missed all flights by Alaska Airlines (which dominated the cheap flight choices on all other sites). Out of the 53 options they gave us, the only one that fit our time criteria was on the third and final results page. This flight was $249.00, almost $60.00 more than the best price on every other site. (2 out of 10)

Buying – Except for one meager car rental offer, Hotwire got right to the point, and we entered our details with little fuss. Their Trip Protection offer was $13.00. They didn't ask if we wanted to reserve seats before booking was complete. At least the process of buying was quick. (8 out of 10)

Priceline
Searching – Priceline's search box didn't allow us to enter preferred times which meant the results for departing and return flights came separately, but desirable flights were high on the lists, so it's efficient enough. (6 out of 10)

Buying – On the first confirmation screen we had to scroll past Trip Protection for $15.00, rental car quotes, airport parking and a few offers for attractions – not terrible since all the add-ons were relevant and on one page. On the following screen we entered our details. With one final click, we completed the purchase, but without a chance to choose seats before committing. Priceline does try to up-sell, but in a streamlined way. (6 out of 10)

Kayak and SideStep
(These sites are bundled because, once again, they behaved like identical twins).

Searching – On both sites we could enter a range of times. Both results page put ideal roundtrip flights on top, even though slightly cheaper flights were available at different times of the day (and could be viewed with one more click). The sites showed where we could get the best price with our next click. Ten seconds later, we were looking at our flight details on the Alaska Airlines site. For this test, Kayak and SideStep were the fastest and easiest sites to use. (10 out of 10)

Buying – It was difficult to judge the buying process using Kayak and SideStep because they send you directly to an airline site, or another low cost booking site to actually make the purchase. The lowest prices were usually found on airline sites, so we tested all the major US carriers starting from where we arrive after these aggregators drop us there.

Delta offered a lower price flight than the one we chose, but at a time of day outside our range. Aside from this helpful gesture, all the airline sites we tested provided a no-nonsense buying experience, usually with a choice of seats before final confirmation.

Many previous tests have demonstrated that these sites often fail to successfully get the user the offered deal on the actual booking site. This will probably happen less as their software improves, but when it does happen, it can stop you in your tracks since you see your top choice as available, yet completely unobtainable. (6 out of 10, with two points deducted for a not insignificant failure rate as of now).

Conclusions

Kayak and SideStep provided a simple path from search to final confirmation, which made them the clear winners in this test. Their noticeable failure rate should improve as time goes on, and when things go right, they can help you book a ticket quickly. You can be confident you are getting a low price.

When you want to cut to the chase and just buy a ticket, Orbitz and Priceline are less annoying than Expedia and Travelocity. Expedia in particular piled on so many confusing and irrelevant offers that we became demoralized and might have canceled the trip altogether if it weren't just a test. Travelocity is much nicer in that regard, but the evil blocker-defying pop-under seems insulting on a site that wants us to make a major purchase from them.

Notes on the price issue
These tests were performed over a couple of hours. Still, a clear price trend was noticeable and worth mentioning. In results that mimicked our previous tests based only on price, Expedia, Orbitz and Travelocity found the exact same flights as Priceline, Kayak and SideStep, but the first group charged around $5.00 more than the latter group for the exact same seat.

Hotwire's inability to find the cheaper Alaska Airlines flights the others found would have cost us around $60.00 more for the trip. Again, this happened a few times – a fatal flaw in our book. Even if it were easier to use, we'd never book a flight on Hotwire without checking elsewhere first. And that being the case, there isn't much point in using it.

Next week
We've tested the sites on prices, and on ease of use when you know what you want already. If you have a flexible schedule and you're interested in finding the lowest price over a long span of time, your priorities are different. Some sites make flexible searches much easier than others.

Stay tuned for: Which site is best if your schedule is flexible?