My old android was buggy as hell, but my Samsung Galaxy S3 has been great since I got it nearly a year ago. Never restarts, never freezes, and it's never slow. It's a fine phone.
In any case, you already HAVE a smart phone. You don't have a Vita. What's the point in upgrading now when you know there will be a new, better model later this year for the same price anyway? The Vita at least isn't going anywhere, and it'll offer a new experience, plus there's a good number of fun games out for it now. Go get one.