I've found in all locations that letting the CFLs warm up (maybe up to 2 minutes) has produced a brighter environment than the incancesdents they've replaced. Probably at or near the rated comparison most manufacturers include on their packaging. The highest a wattage bulb/ballast I'm using is 23w.

The buzz is definitely a product of an inferior ballast. I've also found that certain fixtures may contribute to the issue though. That is to say, fixtures with anything in them other than straight electrical wire, such as a ceiling fan. Right now the only bulbs in the house that make any type of sound are those in our small (powder) bathroom. They came with the house, but I have some others here I've bought myself I should try eventually.