I recently flew Southwest from Seattle to San Francisco and back. I flew out on the earliest flight at 6:20. I had lots of space, I slept like a baby, and even got there early. There were a few talkers, but they weren't disruptive. I woke up in time for the the landing--easiest flight ever.
And then flew home midafternoon on Saturday. Biggest mistake. The plane was booked to capacity. Worse than that, there were more than 5 misbehaving kids on the plane. Maybe it's the single person in me talking, but I know kids need to fly, but really do you have to take them along if you can't control them?! What about the other passengers? From the kids standing on the seats, to the babies wailing, to the children's DVDs that were playing loud enough for me to hear the singing, I couldn't wait to get off. The flight dragged and dragged.
On the plus side, flight service was very friendly, and the ticket was very reasonable.