I am surprised to hear of a rough running Brute. Maybe the changes They have made since I got mine are causing this. Also mine is relatively quite.
CBM, My Gem CBM is a noisy beast. My Porta scrub (Sprint) is quite as a mouse. My GLS should be here Tuesday so I will follow up once I use it.
I have never used a Cimex, but if the right deal comes along I would snap one up.