I know the OP isn't interested but others may be - I use the Milwaukee 18v shop vac for work and have been pretty pleased with it. No, it's not as powerful as a corded big vac but it's small and actually does pretty well on water which is important for me as I work on yachts. The run time is pretty good since you don't generally run the vac more than a few minutes at a time...it's not like you're vacuuming a whole house with it. Mainly I like it because of the size and convenience of being cordless. It's often a hassle for me to have to string an extension cord down to a bilge or engine room. If somebody is already carrying cordless tools, it's a good addition.
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Although I haven't tried one in years, I hear the latest versions of the black and decker dust busters are pretty good. Far better than the old 80's things I remember.