My big issue with BioShock 2 was that it never felt like anything more than a really uninspired retread of stuff the first game did so much better.
Also, considering you're a Big Daddy, you're made out of tissue paper. I get that they can't make you unkillable, but you were so squishy when you're supposed to one of the BAMFs you repeatedly fought for your life against in the first game. At least when the original makes you a Big Daddy it's right at the end, when they could add in an appropriate level of empowerment.