dsalmon55 - You mention one degree difference. I'm not sure how you cab be so accurate. First of all, you probably already know that if you are plugged into a 20 amp circuit; only one AC can be run. I fine that having the vent right beneath the AC open that the AC is less restricted and really pours cold air out. However when I am inside and want quietness, I shut that vent. I also once having the moho cooled, run the rear AC with all the rear ceiling vents closed (primarily in the evening). The rear AC now will come out the front vents with great quietness.
Even with shades closed if bright sun is beating down on the moho, the moho is a can and heats up easily. Achieving more then a 10 degree differential is sometimes difficult if in hot sunlight. Besides temperature, the reduced humidity is a benefit, even if the temp is not down where you want it.
Tip - Get shady campsites, especially when down south,
Gale & Hank- 2012 Berkshire 390BH