I had Armour 2 (Being a Big Daddy too) and Electro 3 and eqipped the shotgun. Finished off the Boss (Fontaine, right?) in one go round. Even when the Splicers and the little whirly birds came by I ignored them and my power was at 9 and 6 when I finished them all off. Horrible easy as pie ending to a great game.
I thought that Bioshock's ending was an improvement over the ending of System Shock 2, the spiritual predecessor of Bioshock. The ending of System Shock 2, I thought, was an uninspired and unimaginative letdown to an otherwise remarkable game. Bioshock had your typical first-person shooter ending, where you have to defeat some gigantic monster to finish the game, but it was better to play it safe than spoil a great game. In fact I was somewhat disappointed with Bioshock's ending, but some rules were made to be broken and some weren't.