No I haven't player Ever17, but have read a bit about it on various sites. Might get around to playing it eventually. I agree, it definitely finished with a lot of questions and not so many answers, which at first made me dislike the ending a bit. However after sitting on it for a bit I actually think I enjoyed it more than 999 overall. 999 was helped I think by the fact that I didn't really know what to expect when I went into it, where as this game I was a bit more prepared for all the science fiction stuff.
I'll send you a pm I sent Nabe about it! Also have you seen much of the stuff about the 3rd game? It's a mix of speculation and mild spoilers but some of it is very interesting!