My initial impressions exactly. I picked one up last wed, Only used it once to sand a kitcken I skimcoated. took out the little ridges nicely and minimal dust. I hear ya on the disks, 5 for $40 up here. Will incorporate an average price for 2 into each job from now on.
I am not running their shop-vac either, manily because of the cost, was $299 at my tool place.
Tough to get into corners where they meet with the cieling for example, but save alot of time and cleanup in open areas...
Jim