Simon you're spoilt with your tm so comparing yours to the etm is a bit silly yours would suck it up. I was suitably impressed with the etm at 100ft, I used my bane with 2 vac blowers it was quite a hassle.
IMO if you get a tm get one from a supplier you like, also I'd get a big one the engine will not be running it's knackers off.
Shaun