"loudness" as you put it, is a matter of mastering. you can get more than enough headroom with 16bit/44.1KHz. and finally, as cliche as it is mentioning the loudness wars and stuff, I'll keep it short and simple: loud does not equal good.
personally, I just record with that setting, because it, like the people mentioned before, saves space and CPU while recording, and I don't have to convert it back to 16/44.1 for distribution. also, I don't have half the skills of professional engineers, so chances are, even if I recorded with higher settings, I couldn't get it to sound any better than what I can now.