Using the Bosch Multitool today to sand down filler in the ceiling. Had it plugged in to the Nilfisk vac. so that the vac. wasn't running all the while. Realised that the suction wasn't up to par (it's usually v. good - sometimes too much so) and eventually realised that as I lowered the speed on the Bosch the vac. slowed down. This doesn't seem very useful, especially as the suction drops off so rapidly (square?). I've not had a chance to test other tools, but the facility it almost useless on the tool where it's most needed (of course).