Never used flap-wheels outside of auto/welding applications, but I'm glad it worked for you.
In terms of angle grinders... Metabo. I've used them for a long time, and IMO they're the best on the market. The anti-kickback system they have has saved me a couple nasty accidents when cutoff disks shattered, and the grinder braked instantly... Great motors, smooth running, good ergos, never managed to kill one... Love 'em. Good brand also for corded drills.
Bosch used to be a quality standard 20-years ago (A Bosch jigsaw was like a Milwaukee drill: the gold standard.). Today, they're not made how/where they used to be, and I've been very disappointed with the latest Bosch equipment I've used/handled.
Big fan of my Festool, too. Great brand when you want fine tools for more precise work... Big prices, though. Especially after their last two rounds of price increases...