I have used several brands, in serious settings. Milwaukee, Metabo, Hitatchi, HF orange, HF red, Makita, DeWalt, Lowe's, Skil etc. I've picked up a bosch to use, but never put much time on it. But Bosch is the owner of skil.
My thoughts:
1) Milwaukee. Good Product. Not without faults. Get highest amperage you can find. But idiots exist and as my father said "Some people can tear up a steel ball in a sand bed."
2) Metabo. Good product, but not what people say it is. Get the clutched model. But once you get in a regular habit of slipping them, they slip easier and easier.
3) Hitatchi. Good product for the price. Buy 4 and keep a different wheel on each one, and put the 4th one up.
4) HF orange. Save the brushes they send with one. But never had any issues with them except the fact they are low amp rated. Use accordingly and let the grinder do its job and they last. If not, watch the smoke. I miss those because they were good for certain tasks...but they've replaced most of them now with the red product I think.
5) HF Red product. Nope.
6)Makita. Works well while they last. Never had great luck, but some people swear by them. I burned up mine quickly when used under comparable conditions to similar amped models.
5) DeWalt. My favorite. If anything, you can see it with the bright yellow. But I don't buy less than the 10 amp. They have a 13 amp model...which I like. But I was on a job installing burglar bars on a restaurant. Had a new HF and just happened to be fairly new DeWalt on the tailgate of my truck connected to my engine drive. Walked into the restaurant to check out some installation issues. Came back out 15 minutes later and the orange HF walked off, and the Dewalt was still there. Go figure. Also they have newer designs with a special vent that keeps the sparks from getting into the motor works on some of them. Easy to use and adjust spark guard.
6) Lowe's. I think my brand at the time was GMC? Good product, variable speed, but it had its limits. Never burned up or smoked it, but did wear out the brushes. Need to fix it. It was great as a cup brusher.
7) Skil. Run and hide. It's not the grinding disk throwing out smoke.
8) B and D Orange Crap storm orange things. Lasts longer than skil...but don't hold your breath for more than home owner expectations, unless it starts smoking.
9) Bosch. OK...but I can't get away from the thoughts of a skil being from the same company blood.
But above all considerations, look for this:
1) Amp rating. It's the great equalizer and only way to truly compare. That will tell you expected duty and life span of the unit. 7 amps is not great, but tolerable for light stuff. 10 amps minimum for pro use. 13 amps are better, especially for a 4.5"
2) Extra Brushes. They all wear out.
3) multiple possible handle attachment points. 3 is good. 2 ok. 1...pass on it.
5) Easy to disassemble screws and brush openings. If its sealed up looking pass on it. No screws? Run.
6) Easy to access and operate Disk lock pin.
7) Easy to remove disk. I like the Dewalt hand remove, toolless design. Not all of them have it though.
