They don't show up when they say they will. They do shabby work at best. Our builder Ashton Woods used them, but then dropped them because they are so horrible.
If you are going to use them, get used to taking lots of days off from work as they will first schedule to come out and see what they messed up. Then schedule a repair for another day. The day the repair is supposed to be, they will verify they it need to be fixed and schedule another day for repair. Repeat these steps until you've missed about 6 days of work and they will have done what they say is a repair.
Then you'll get a quote from someone else to fix it right, just to find out that you've over paid for horrible services in the first place.