I'm not remotely interested in handheld consoles, since I'm in college and I don't commute anywhere.
However, from the very little I saw of the 3DS and the little information I know about Vita, I would definitely prefer Vita.
The simple addition of a second stick seals it for me. With that you can control a lot of genres with a lot more ease (especially with shooters). Graphics aren't important for me, but the graphics I saw when I played with the 3DS just seemed dated. It's really annoying seeing so many people getting excited over re-releases of old games when they've already played it years ago and there's not much improvement/change. I really would like to be able to enjoy a new generation of games and have hardware that'll be able to support it.
The 3D effect just seems gimicky, whereas all the other features of the Vita seem more concrete (touch is meh, but I guess that's what Sony wanted to make Vita competitive to the DS and smartphone market. Battery life does seems like a huge issue, but as I'll be more of the casual player, I really don't need anything more than 3-4 hours a day while I commute on a train or bus.
Ultimately, it's down to the games, and like I said, the simple addition of 2 sticks opens up a huge number of doors for future games for the Vita IMHO.
