I have a 5hp Rigid shop vac that I like. I've had a few others that all did the job, but where a pain in the but to haul around. I like the Rigid because it is square and everything fits into it like a tool box. I can stack other tool boxes on it and there isn't anything laying around. Space and a clean job site are a huge thing for me, and my clients all comment on how nice it is. The filter is the drawback to it as it clogs up pretty quick with drywall dust. I usually take it outside and clean it over a bucket a few times during the job, then buy another new filter for the next job. I build the cost of a filter into my jobs so it's just part of doing business. 5 hp is plenty powerful enough to clean out the grout lines in tile, get all the dust out of a hole drilled into concrete and clean up every corner of dust. It's kinds of small compared to the others, but since I clean it out every day, smaller is better because it takes up less room.
Eddie