I've been through it 3 times now, once on each of the difficulties.
The first time it was an engrossing experience.
The second time not so much but still an entertaining romp through Rapture, there had been something like an 8 month break between plays.
The third time it was really unsatisfying, it just felt like going through the motions, and I was kind of glad to get to the end so I could move on to something else.
Weirdly though, I've just watched a Bioshock walk-through on YouTube and the guy played in a completely different style (shock & melee) to me and now I'm like, hmmm maybe in a few months time I might try it that way and see what happens.