Since we've gotten into HF tools, I'll add my 2cents. As far a grinders go I have several including Dewalt, Black&Decker, and HF. They all work "fine" - they grind and cut just like they are supposed to and you can't tell the difference when you're done. However, I reach for my Dewalt first because it is just so much nicer to use. When it comes to HF motorized tools, my feeling is that they are fine #1) if the person already knows how to handle that kind of tool #2) for the occasional user where the results don't matter. HF tools have their place, but I'm pretty much with Eddie Walker on this.
Here's an example to clarify what I mean: I learned wood turning on an expensive lathe (about 10x the cost of a HF machine). I can use that knowledge and skill to get good results from a HF lathe with a lot of effort and difficulty that would not be necessary on a better tool, and that someone trying to learn would get very frustrated with and probably give up. (And, yes, I know a lathe is not in the same ballpark as a grinder, but this is intended as clarification for what I said in the first paragraph.)