I'd prefer a weaker system with better battery life. I could play my Neo Geo Pocket for a week and then put it in the closet. Six months later it would still have plenty of battery left. I cant even get through a plane ride with the PSP and by all accounts the 3DS and Vita are worse.
That said I did pick up a PSP in anticipation of all the awesome games it would have and feel pretty burned about that. I've had the system for like 5 years and have only like 7 games. I'll pick up a Vita once I feel sure that the library is gonna be there to make it worth it (and no Im not interested in Uncharted)