It's my excuse for buying things!
I'm also wondering how the M12 and M18 vacuum work as well. Might be handy to grab the small M12 to keep the workbench area tidy.
I haven't read anything good on the M12 vacuums, but I have the M18 Wet/Dry vac and I really like it... I use it for everything from cleaning up my garage messes, to pulling a clog out of the drain in the condensate trap in the attic and cleaning out vehicles. That's another tool that really likes the 9AH battery.