I've felt that way since I've had mine but I downsized from a 30' Sunnybrook with ducted AC in my "old" age to make camping easier. Always wished that the compressor and the fan would both kick off when temperature was reached. There must be a way to make it do that but don't know what the procedure would be. We now run ours on low almost all the time to cut some fan noise but maybe we are just getting used to the noise. Regardless, we still like our 2109S as it fits us perfectly.
2002 Silverado 2500(160K miles)
6.0 Liter, 4:10 rear
2012 Rockwood MiniLite 2109S