Bloated? Opera weighs in at 3.59mb (win) and Firefox at 4.60.
Both are good browsers imo. Opera is a private (don't think they are publicly traded) firm and requires sources of revenue to operate. So it's either ads or browser sales that keeps them on the map. Personally, I like their product enough to pay for it. Choices & competition are generally a good thing.
Bloated? I believe IE is quite large.