While I enjoyed it, the game became rather repetitive after not too long. There are only, what, 10 enemy types in the entire game? I also didn't feel like the gameplay evolved enough as I went on. Once I learned the basic strategies regarding how to kill things, those never really changed throughout the entire game. Then again, I've been spoiled by breathtaking FPSRPGs like Deus Ex which had everything Bioshock has and so much more.
Also, I thought the storyline was a bit on the weak side, and very clichéd in some places. Zero Punctuation's review really was spot-on: your character can do pretty much everything right from the start with little to no real "leveling up" aside from equipping new tonics which don't effect gameplay with as much severity and the "choice" wasn't much of a choice at all.
In Deus Ex, not only do you get the chance to make crucial decisions which effect the gameplay, but there are situations where your friends can die but there is actually a way to save them all if you're good enough and they'll be alive at the end when you have to decide between three different choices which all give you different and yet appropriate endings.
Let me put it this way: in Deus Ex, you were given upgrade CHOICES which actually effected how you would play for the entire rest of the game with no going back. For example, one upgrade you found would either equip your character with a static field which detonated explosive projectiles which were fired at you OR give you a small probe robot which you could use to search the area without triggering any alarms or alerting any enemies. But you could only pick ONE of these and then upgrade its potency as the game went on, which means that the static field worked from a greater range or the robot probe could be detonated (meaning you could move it up behind an enemy's head and explode it).
In Bioshock terms, imagine that, instead of getting the Ice and Fire plasmids, you had to choose one and ONLY one, but you could then upgrade it to give it different abilities which greatly affected how it functioned, like the Fire plasmid, when upgraded would cause enemies to explode if they died on fire, damaging other enemies around them, or the ice plasmid was upgraded to freeze enemies so solid that you could lift them with your telekinesis while they were frozen but still alive and then hurl them against walls or throw them, alive, into hazards.
If you're used to Halo, yeah, Bioshock will seem awesome, but if you're already a FPSRPG fan, Bioshock is FPSRPG "lite".
And frankly, looking over this thread makes me angry that pioneering games like System Shock 2 and Deus Ex never really got their day in the sun while Bioshock, because it had a huge hype machine behind it, is getting all this praise when it's probably less than half the experience these other games were.
I'm not trying to sound like an ass, but really, I'd recommend picking up one or both of the aforementioned games and getting to know the roots of the FPSRPG genre. If you liked Bioshock, you'll probably disappear for a week with Deus Ex...