I agree Dark Souls 2 is better than the first overall. I feel like DS1 had better level design with the way it was all layered where as in DS2 its all sort of spider webbed out from Majula. Combat in DS2 is actually better and less gimmicky because it focuses significantly less on how many invincibility frames you have while rolling imo. The bosses also reflect this and are a bit more fair to someone that doesn't just roll through pretty much everything and instead blocks. Sticking to the left leg got really old though they probably should have swapped which directions you could dodge the ability from the easiest around more than they did. The atmosphere/music is just as good and the story just as deep if you look for it. It's actually directly related to the first dark souls and there's A LOT of connection between the two which is probably why its Dark Souls 2 instead of X Souls.
Only boss I'd really say was reused was the old dragonslayer. Essentially just half of a darksouls boss but that was fine. I was personally happy to see the guy and it wasn't a very pivotal part of the story or anything. Just a cool throwback and interesting moment for anyone into the lore trying to piece together how he could possibly be in both games.