Was just out in the shop working on a metal project and using my Chief 4.5" angle grinder to dress some welds. I have to say, it's amazingly quiet, much quieter than any electric angle grinder I've ever used and well balanced and very smooth too but what really got my interest was, because I like to look 'under the covers on power tools' was the grease ports in the gear head. There is one in the front above the spindle lock, a removeable screw that accesses the gear train that you can apply grease in and another on the top of the polished aluminum housing that is a needle grease port, just like my high buck IR impact guns have so greasing the gear train is easy (even though there is no mention of it in the included instructions).
This tool is built to last a long time. I'm impressed.
Usually on corded angle grinders, first thing I do is take the head apart and replace the 'smooze' grease that is usually inside with quality synthetic grease, which helps them but I tend to find the smoke in the motors anyway, especially the cheap (and noisy) HF corded grinders. What is inside the cheap HF and other cheapo grinders don't even look like grease, looks like fish guts and everyone is noisy and everyone gets hot pretty quick. I don't baby any of them, I run them hard or until I find the smoke and I'm good at that.
Peering in the Chief, looks to me like it's filled with quality lubricant too. I'm impressed, but especially impressed with how quiet it runs. No geartrain noise at all, just the air exhaust and even that isn't bad. it's well worth 100 bucks.
First time I used it hard.