I went to the midnight release of this (I don't know what compelled me to when i could have gotten it after work today) and played it for just one hour when I got home. It's excellent
I just got through the first assassination and I have to say that I'm loving the slightly sped up combat, the more fluid climbing, the hidden blades in combat...
My only gripe is that the faces sometimes look a bit PS2ish, specifically Lucy. What did they do to her? For a collection of pixels in a game, she was relatively hot in the first. Now not so much. But that's just a little thing. the actual gameplay is visually beautiful.
15-20 hours for the sequel of a game that you could easily beat in 6 hours is really very enticing and pretty impressive.
all in all, my first impression i that this review was right on the florins.