We use more for rough shaping with the merlin burr disks in wood and foam. The sanding is also more shaping than finishing. Haven't noticed the high rpm being a problem four this. We're using 40-80G, so the abrasive clears pretty effectively rather than clogging/burning like it might if it were 120G+.
Kevin Groenke
@personmakeobject on instagram
Fabrication Director,UMN College of Design (retired!)
Proxxon and Merlin 2 are not the same handpiece. The original Merlin package used the Proxxon mini grinder but the Merlin 2 is quieter and cooler. The Arbortech is a good tool but since it is powered by a full size 4.5" right angle grinder, it is heavier and more tiring to use. Flexshaft right angle tools are handy, but less nimble due to the need to avoid too tight a loop on the shaft itself, and they require a light touch more that the Proxxon and Merlin 2 do, to avoid twisting the cable that powers the tool. Air tools require a substantial air supply, which is great if you already have a large compressor, and don't mind powering a 1/4HP air motor with a 3-5 HP electric motor. Pluses and minuses with all the tools.
I cast my vote for the Arbortech minigrinder. Lts of power and easy to control.