I really enjoyed it, beautiful world and art design, interesting characters and story and the combat though not perfect is more than engaging enough. It's not as good as Bioshock 1 but that frankly was and is a masterpiece.
From what I've seen on this forum most of the people who didn't like it seem to say so because they prefer more "standard" FPS games (perfectly fair) or couldn't follow the plot (not the games fault) or just played it because of the hype when they were never going to like it in the first place due to their own preference for other genres.
The combat in infinite is not perfect, however you aren't supposed to play it like a normal FPS i.e cover hugging, plasmids, skyrails, clothing augments, tears and scenery are available to you for a reason, if you actually make use of them the combat can be incredibly fun (melee focused skyrail builds are hilarious), if you don't I can completely understand why people wouldn't enjoy it, but the same could be said about playing Skyrim and cheating yourself full Daedric armor at level 1, yes you CAN do it but why would you want to?