AHS has been fine for us.  We've never been denied coverage.  The contract terms limit coverage for some things (like, they won't put sheetrock back to finish condition, and they don't cover icemakers), but I think every year we've come out about even with the $ we've paid in, one way or another.  They are kind of like the HMO of home repair service, in that you have to use their network of tech's and wait for them to come out - and sometimes it's 1-3 days before they can get to you.  But we've actually used both the plumber and HVAC tech's AHS sent, to do other work for us, and we like them...