A classmate of mine in welding class back in 2000 was bringing those grinders to class; they were only $19.99 even back then. How long did they last? 20 minutes!! After the 3rd one, he finally gave up and bought a DeWalt.
I haven't had luck with the hf ones either, but my dewalt ***** ***, also.
My 7 amp Milwaukee runs laps around my 8.5 amp Dewalt, and the dewalt sounds like it's crushing gravel. I bought the Milwaukee as a backup/wire wheel grinder, and within 5 minutes of opening the box, it got promoted to grinding duty, and the Dewalt was sentenced to life with a wire wheel. After 3-4 years of homeowner use, the Dewalt is already reaching it's life limit, I'm afraid.
I'm also not nice on grinders, but still.
HF is great on returns, way better than any other place. I went in to buy a new 6' 20 lb digging bar, as I was being a tard and using it as a prybar when I shouldn't have, and bent it. A manager happened to catch me and ask what I was looking for, and I told him I was looking for another one as I had bent mine being a *******. "Bring it in, we'll just swap you out." "umm ok, but it really wasn't the tools' fault." "no matter, bring yours in."
sho'nuff, 30 minutes later I had a free new digging bar. I also had a broken socket that may or may not have been HF. (Again, ******* syndrome. I was trying to get a bolt loose on the trailer, finally had a breaker bar and cheater pipe and was giving her hell when the socket blew up. In hindsight, I looked behind and found out that when welding the nut to the trailer frame, some genius zapped the bolt and welded that to the nut.)
He said "well, it sure could be one of our old ones", walked off and came back with a full socket set. "Umm, I only have one." "This is how they come." Holy ****. "I'll just buy the set." "Nope, it's warranty."
Alrighty then. Two things they had no need to warranty, and I can't get sears to warranty true defects half the time. Guess who gets business first on stuff that will be foreign either way?