Really? Other people with review copies have said that the game really doesn't need you to play 999 before this. From what I've heard, it explains everything from the first game, so you won't be left out in the cold. You just miss out on the first game and all of it's plot twists. You will probably enjoy it more if you know what happens in the first game though.
I had to comment on this, considering I just finished VLR today. It'd be a massive mistake to not play 999 before VLR. Yes, they go over a lot of what happened, but they don't devulge many of the details. So yes, you would get an explanation of the plot for the first game if you play VLR, but you'll be missing out on the experience, characters, and many of the twists. Personally, I enjoyed the first game more, but VLR is still an amazing game. One of the best games out for 3DS/Vita.
Oh, and for anyone wondering.. the controls for the Vita version are fine. No idea where this talk came from for it having poor controls, but I only had minor frustrations with the controls for 2 of the puzzles (which didn't bother me much, and can easily be fixed if you use a stylus but I didn't have to).