Alex said:
But as soon as you go do some general clean up, you're struggling to get your dirt from the floor with these Festool vacs. And guess what, if you're making things dirty you also have to clean them up so I consider clean up a very important duty for my vacs. Especially if you connect the tubes with a floor nozzle, suction is horrible and it is struggling to pick up larger lumps.
I think the confusion here may be the difference between suction and airflow. For scooping up lightweight dirt and dust over a wide area, as you've described, airflow reigns supreme. A heavy-duty shop vac like the Ridgid HD 1600 that I use as my general-purpose cleanup vacuum can pull much higher airflow than the Festool vacs, in this case about 200 CFM versus 150 CFM on my CT 26 (assuming both have clean filters). That translates into much better pickup performance over a dispersed area.
However, it doesn't exert as much actual suction (which would be its ability to lift and pull along heavier debris, or to break up blockages inside the hose). My Ridgid in this case pulls about 2/3 of the suction of the Festool in a water-lift test (which is the standard way of measuring suction power). A large part of the reason for the disparity is that the Festool is fully sealed and filtered across its entire mechanism, and the Ridgid is not. Adding filtration lowers airflow but improving sealing increases suction.
I can mount a HEPA filter in the Ridgid so that it has more comparable filtration to the Festool, and it loses about a third of its airflow if I do, which actually drops its performance below the CT. (I've got an anemometer and have actually measured this just for curiosity's sake.) Their motors are roughly equal in power, but the CT has a tighter seal so it's leaking less air from places other than the hose end.
If your argument is just that a HEPA-certified dust extractor isn't as good of a shop vac as a shop vac, then I don't think we have any disagreement. They're tools aimed at different purposes. Festool actually doesn't offer a filter as coarse as the Ridgid's (the coarsest filter they sell for the CT is equivalent to Ridgid's 1 micron "fine dust" filter, which has lower airflow than the default filter), but if they did, you could presumably slot that in and it would get slightly better airflow than the Ridgid since their motors are both 1200W and the seal is tighter. In that case, you'd have turned the dust extractor into a (very expensive) shop vac with both its strengths and weaknesses.
Alex said:
I don't know about your tests, they're always very limited in time and circumstances. My experience isn't. All nice and easy to test a tool when it's brand new, with new bags and filters, but did you know the suction of the Mini and Midi drops to half when the bag is only 1/4 full with dust?
The test I linked specifically accounts for that. They measured them with clean filters and then sucked up about 20 lbs. of drywall dust to deliberately clog the filters and tested them again. The CT 36 showed some of the lowest loss of suction and airflow of any vacuum in the shootout (only Makita did better). They didn't test the Mini/Midi, however, so maybe they have very different performance characteristics than the CT series.
Edited to add: one other factor I forgot to mention is the hose! Larger hoses increase airflow and reduce suction. Large shop vacs (at least in the US; I'm not sure about elsewhere) usually have a 2.5 inch/64mm hose, while the largest Festool hose is 50mm, and most people are going to be using a 27mm or 36mm for their tool hookups.
