It's working well with X3, and a few bugs have been fixed, which I'm fairly impressed by, given that it's basically discontinued. However, the indications are that Cakewalk aren't going to do much more with it; Noel has been talking about open sourcing the V700 code. So... hmmm. It really is an excellent bit of kit, but what lifespan it will have is anyone's guess.
It's also worth noting that both X1 and X2 broke all kinds of functionality, and while it's more or less back to where it should be with X3, it's hard to feel confident about the future with it. I'm sure it will become less and less of a priority, and I know that internal testing of v700 compatibility is less than rigorous. (Sorry to say, but them's the facts).
That price is really a bargain for what you'll get, and as an overall setup it works really well. I'm just not sure how future proof it is. I use mine all day every day, I will say that. It will be painful when and if a Sonar update that doesn't work with it arrives. Indeed, as I say above, that's already happened more than once, and it was indeed painful.
Not trying to put you off, or criticise anyone, but I think it's best you go into it with your eyes open.