I have a Metabo GEP 710. Variable speed with a paddle. I think it's a 6.4 amp, made in Germany. Can't complain so far but it's the only electric die grinder I have so I can't say if it's better or worse than the others. A little pricey, I got a good deal on mine but I think CPO has them for $250. I expect it to last forever but if something does **** out I would guess it will be the variable speed dial.
I kind of wish I had a toggle switch so it could be used in more positions and with a side handle, but it hasn't been an issue so far. One thing I like compared to some of the electric ones and all the air die grinders I've used is it has a lock button like an angle grinder, so I can change tools without needing two wrenches. I have mostly used carbide burrs, for which I just crank the speed pretty high, but it's nice to be able to turn it down for some brushing operations, and I have a cutoff wheel mandrel too. I think the book that came with it says what RPMs each number on the wheel is, but it's infinitely variable so I just try to get it close to the max for the tool.
I don't think I use any one tool enough to have a second grinder with that tool set up in it, but if I did I'd probably try to find a used on on craigslist or ebay. If you're just going to have one, the spindle lock button and the variable speed are nice features to have. I can't imagine trying to use a 3 inch cutoff wheel at 30,000 rpms and riding it into a low earth orbit.
