The 3D effects are actually kinda cool in some scenes. I turn it on from time to time to see what the developers made it to look like. However, 3D is an awful way to play games. 3D is a strain on the eyes, and you have to sit in a specific spot for it to even work well. Who games completely still?
I like my Vita, but I have more games for my 3DS. As a result, I have played the 3DS more. A lot of Vita games have console counterparts. I don't know about other people, but if I had a choice between handheld or console, I would go with console. I think that hurts the Vita.
I play a lot of RPG's on handhelds, and I am beginning to think that a lot of other people do as well. As it turns out, the 3DS has more accessible RPG's. The Vita doesn't have that many RPG's. Its best RPG are probably Persona 4 Golden and Final Fantasy X, but both of those are actually remakes of older games. Even with YS, Legend of Heroes, and Tactics Orge, that's nothing compared to the 3DS. That being said, I think I might do a Vita game next.