The thinner cushions on SW make them too low for me. That was another complaint I had, plus I felt like the seat was trying to make me slide forward It was a very odd feeling. The flight was less than half full so I moved around to a few other seats to see if maybe I just had a bad seat but they were all like that.
I've flown on AA since they added rows and had more legroom than I had on my most recent SW flight. Plus on AA and other airlines I can opt for more legroom by paying more, which is worth it to me.
I'm waiting for JetBlue and Virgin America to start flying routes to places I travel. I've got friends that fly on them and have nothing but good things to say.
I've flown JetBlue. The planes are nice, but they are limited and their strategy of locating at airports like JFK just begs for delays. Virgin anything is supposed to be good. They are niche airlines, though.
I can't say I agree with every move Gary Kelly has made (e.g. the new no-show policy is too harsh, IMO), but among the big airlines Southwest is still the best, IMO. I don't like the "Economy Plus" sections on other airlines. First, they provide almost too much legroom (short of being able to lie down), putting the table too far away, without adding a millimeter of width. Second, all the status holders get them for "free" meaning that fewer are available, and the rest of us just get 2 fewer inches than normal.
Beyond that, Southwest has other advantages. Open seating just makes a lot of sense to me. The employees seem to like working there (I couldn't say that about the flight attendants on my American flight the other day). They are pretty good about fees, too. Most of their ancillary fees are for things most people can live without (e.g. early bird check-in). The biggest difference is that Southwest actively discourages standby since they only allow it with full fares. It probably hurts them with business travelers but it also helps make it easier for them to predict flight volumes.
I've taken advantage of the "no change fee" policy a lot. As soon as I know I'm traveling for business, I'm on the site making a reservation, knowing that I can change it later if something comes up. The other airlines like to nickel-and-dime, with some of the worst ones even charging for carry-on luggage and non-alcoholic beverages. It will be interesting to see if others follow Southwest's lead and strike deals with media companies to offer entertainment with no extra fees.