OK, so the CFM issue is likely the main reason why the shop vac doesn't do a good job collecting all the dust from the sander, for example. It certainly has the 'torque' (vacuum in inches of water) to pull in what it can capture, but the capture range is very small because of the low 'speed' (CFM air movement).
Now I get it.
Maybe I can steal my Dad's system while he's not looking....
