I honestly don't understand a lot of the bad reviews. I beat the first one twice with all of the DLC. First of all, it's unfair to compare years of DLC's against a brand new title, so I won't touch that. The base game however, I feel is at LEAST as good, if not much better. The graphics are fantastic (even though I play on Performance mode).
The smoothness of performance mode is so nice, but the graphic mode does look stunning. The gameplay is so much fun I've found.
Combat is great, parkour is absolutely top notch. I don't remember the skills perfectly from DL1, but I don't feel like much is missing (as stated in other reviews).
The inventory system isn't amazing, but I do really love the way your gear cosmetically reflects your play style. The weapons also seem great so far. I've read in other reviews that a lot is missing from weapons. I really think this is from people that didn't play more than an hour. Because I've found awesome 2H great axes with fire on them, among tons of other really cool weapons.
Overall, I feel like it's a great improvement on the first game. Personally, I think a lot of the bad reviews are from competition trying to make it seem lacking, or from people that just haven't given it a fair chance.
If you liked the first one, you'll love this one!