Re: The Dremel dilemma
I like the solid carbide burrs. They will cut the steel exhaust flanges like butter and they don't get dull very easily.
They are brittle though, and if you let them chatter much they will break. I have re-chucked them after tthey broke with good results, just have a shorter reach.
I use those and the larger cut off wheels for all my dremel work.
Don't bother with stones. They wear down faster than what youi're grinding and they clog up on aluminum.
I don't think a drill spins fast enough for them to do a good job. Like router bits, they rely on very high rpm to work efficently.