I don't think so. I just started Zero Escape and it seems pretty standalone. I'm sure like most things, having played the previous game helps but I don't think it's essential.
Vita version has no bugs.
Yeah, if I could have played VLR on the Vita instead of the 3DS, I'd have chosen the Vita in a heartbeat due to it's lack of save-corrupting, game-crashing bug.
I'm so angry that my game crashed in the PEC Room, even when I just closed the DS (didn't "save" at all!). Lost that entire playthrough because I hadn't saved up to that point (Yes, that's my fault. I know XD).
Haven't played it since, but will pick it up after finals.