Voice of dissent here:
I've been brewing almost 2 years, using BBs most of that time (Ale Pail when I want to top-crop yeast or open ferment), but I'm done with them. For one thing, they're not unbreakable as advertised. I've had 2 break on me in that time - one when full of an Irish Red, slipped from my hands, less than a foot from the concrete basement floor as I was putting it into the FC. Bottom broke, wort everywhere.
The second one just broke this week - filled with PBW solution (water first, then add PBW, as instructed), next morning the BB was empty and close inspection revealed a hairline crack in the bottom. Luckily it was in the utility sink, so no mess. An identical BB in the next sink treated exactly the same had no problem. This was after transferring a brew to 5 gal BBs, so it had held beer throughout fermentation, then must have developed a crack during cleaning.
OTOH, I had a full BB slip right out of the blue handle they make for them, and it bounced down the basement steps - didn't break, minimal mess. Beer turned out fine, but I don't trust that handle style anymore, that's for sure.
Now, a broken BB is a whole hell of a lot safer than a broken glass carboy, no doubt. Safety counts, and I'd never knock someone for choosing BBs for that reason.
I've also never felt confident about being able to get them clean without being able to actually scrub them, either. Haven't had a batch go bad on me, it's just a feeling, but I can't shake it. I really want to scrub it, if only with a soft sponge like I use with my Ale Pails.
I've never noticed any oxidation flavor, but never had beer more than a month in them - the couple times I've lagered, I've done so in corneys, using same keg for lagering and serving.
For my money, I'm moving to glass carboys - 6.5 gallon for extra headspace during primary. They're smooth walled, easy to clean with brush, and there's an available heavy duty canvas bag with handles for carrying that I'll get. If god forbid I drop a full one on the way from the garage brew space to the basement fermentation station, the glass shards will be contained. I'll use locking handles for maneuvering during cleaning, etc.
I wouldn't recommend BBs to other brewers anymore, but I wouldn't recommend glass without adequate safety precautions, either.