I was given a 4+1/2" makita as a gift years ago. I wouldn't have gotten it if I'd had picked one out. 10x1.25 treads, no spindle lock and a switch that I've never gotten used to. :/ I've had to buy a couple (not cheap) adapters for 5/8-11 threads and they are basically stuck inside certain grind stones, until they are used up, since they are a pain to remove etc. :/
As far as just plain old using it... I try it first and only go with the big 7" when I really need to. The little makita is one of my best power tools tho, despite my gripes.
I'm about the cheapest guy you'll ever know and I agree with Andy on this one. Good tools that do the job right or no tool at all is the way I see it. And those cheap grinding disks not only don't cut good they don't wear right. Always having to re-dress them to lower vibration etc. The name brand disks on the other hand are a pleasure to use. The cheap ones aren't worth it, no way, no how.
I hollow grind knife blades using what's basically a homemade bench grinder. I can accomplish that feat because of one simple reason... I learned how to setup and dress a stone for minimum vibration. I'm not looking for a medal;) I'm wanting you guys to understand how much better work can be done when vibration is low. You can feel what's going on, as opposed to being all "sight driven".
I've never needed any vibration damping like that but then I don't use flap disks. I bought a few 1" diameter, mounted ones with 1/4" shaft, and didn't like them at all. :/ I was looking for something to smooth the inside curve/s on the butt spring on slip-joint pocket knives (a stockman has one butt spring and one double ended spring) but even the double ended spring has a couple little inside curves on either side of the center pin.
Flap wheels left lines. :(
What I've found is best= the highest density de-burring wheels you can get your hands on. :) Little 1" mounted ones work like a champ too. :)
Read recently about cellular damage from vibration in my grown up version of "the weekly reader" ...science news. When I was younger I used a jack hammer quite a bit. Funny thing about those and railroaders is, if you forget to take off your fancy-ass RR approved watch it'll cost you more than you made that day. ;)
Alvin in AZ