SA poster on this:
So, as always, for those who are unsure and waiting for review, wait at least until the release date, so you can get a more complete (and less inherently biased) overview. Personally, I already know what I'm looking for in the game, and Buck review reassured me that, yeah, I'll find it there. So pre-buying it today as soon as it unlocks.
Btw, post contains also a more complete summary of that review, in case you're still interested in it. Play time is apparently 24 hours and there are 3 acts + prologue and epilogue. I see it as a good thing, considering that I'm replaying the original to have a save game available for the sequel, and it's really starting to drag in Act IV...
EDIT @Tigranes: According to a poster on the GOG forums, releases on GOG are on 1300 GMT+1, which would be roughly.. 4 hours from now? You'll probably have to pre-buy/pre-load it tomorrow.