My wife and I picked up our Oliver (Legacy Elite II) and left Hohenwald on 6/6 (Hull #84). We did run into quite a bit of heat traveling back to the Seattle area, even up to 105F in Yakima WA. So I followed this thread as we traveled. I discounted the info on noise outside the trailer. Our ac unit is quiet enough outside I never would have thought it was a problem. While home I did watch a video of a conderser fan (outdoor fan) change from 5 or 6 blade fan down to 3 blades to make it quieter on the outside. From what I can see on the parts listing for 47000 series mach 8 they now use 3 blade fans on the condenser fan.
As far as the inside noise, yeah our 13,500 btu unit is noisy and blows powerfully on low. I was expecting to find a possible parts change for the evaporator fan (indoor fan, motor and blower wheel). Unless I'm mistaken all the Mach 8 units (9200, 13500, and 15000 BTU) use the same evaporator motor (part# 1468A3389) and the same blower wheel (part# 1472A1191). The other thing that doesn't add up is the Coleman literature. Their claim on the Mach 8 is that it has the "highest air flow delivery on high speed and ultra quiet on low speed for night time cooling".
Personally I'll live with the unit as I'm very used to ear plugs if I need them, sometimes the noise bothers me and sometimes it doesn't. I do feel it is good to have an ac unit that can cool the trailer at temperatures well above 100. Also noticed that the people complaining about the noise were located along the east coast which has higher humidity and warmer night time low temperatures. It seemed as though in the dryer heat the night time temperatures many times dropped low enough the ac unit would stop or almost stop cycling. We did have our compromise room temperature setpoint at 74. Any colder and my wife complained.