I'm with ya on this, I actually got half way through and just couldn't be arsed. Sold it yesterday.
Not really digging this latest Bioshock.
I suppose the undersea theme held more appeal to me, but there's more to it than that. Despite the undeniable technical prowess behind Infinite, it feels a bit 'light' in terms of gameplay. It's all very basic shooty shooty stuff. Shoot powers with left hand, shoot bullets with right. Get the McGuffin.Open a tear in the fabric of reality. Proceed to next area. It feels clunky and dated.
The plot hasn't really grabbed me either. I'll see it through anyway. but I hope it gets more compelling.