I've had mine for two+ years. It works very well for chalk dust, other stuff, not so much. I still use a small battery operated hand vac for all the other little crumbs of whatever that seem to find the table.
Would I buy another? I don't know, I guess it's a maybe. I kind of think of it as a solution to a problem that I didn't know I had. Kind of like buying a $3,000 cue that makes balls go into holes, when my $200. sneaky can do it just as well.
Or how about those $150 magnetic chalk holders, can anyone live without one?