Bioshock 2 got a LOT of unjustified flack mainly because many people saw it as a quick cash in (even though it came out years after the original), Kevin Levine wasn't involved with it, it added unnecessary multiplayer, and the original didn't leave a lot of room for a sequel so it felt like an unnecessary story. While all those complaints are valid, it didn't mean the game wasn't fun. Yes the story was not up to par with the original, but that's like saying that Steve Young as a quarterback wasn't up to par with Joe Montana. It was still better than about 75% of other game stories, and the improvements in gameplay were greatly appreciated, such as refining the hacking minigames, and also adding the much desired weapons/plasmid functionality at the same time. The biggest knock against BS2 was that it came after BS1. If you liked BS1 and Infinite there's little reason to fear that you won't like BS2.
I agree. Bioshock 2 definitely suffered by virtue of the fact that it was a follow up to Bioshock and a lot of people hated the MP. It's still one of my favorite games, and what Bioshock 2 may have lacked in story, it's excellent DLC, Minerva's Den, more than made up for it. One of the few DLCs I've bought that I thought was more than worth the asking price. Very emotional and worth replaying for the story alone.