I also have a warranty with AHS and this is the only company they use. I found this out because I had been disappointed by their service in the past and asked for a different one when I placed the call. (Hudson Enterprises has done 2 water heater installs for me, they are 5 star in price & service!)
As for today I was put down for a 12-4 pm slot & was really happy when I received a text at 2 that they would arrive in 20 min. Wrong. It was over an hour after that - but they were still before 4. Technician did seem like a nice guy but admitted he was limited to what was specified in the company's contract. When I placed the order I had asked for the entire 2nd floor drains to be cleared, 3 sinks & 2 toilets, he said he could only do the 2 that were currently an issue. He might have been here for all of 10 min. Yay. Can't wait to see how long before I have them come out again in for another $75. I felt kinda bad about my skimpy tip until I realized I gave him a dollar for every minute he was here.