Yes, we do have a second AC unit on our rig and have used it once or twice. I would say that the main unit works well, but it takes a bit to cool down the main living area. The second unit is in the bedroom, which is usually warmer. So, having the second unit to help cool it down (fast) really helps.
I don't think you'll have cooling issues, using the main AC unit. It may take a bit longer to cool the bedroom. We found, also, that if we turn on the exhaust fan in the bathroom, it helped circulate the air better as well.
Congrats on your rig and don't forget to post some pictures. From what I saw, Jayco has made some large changes in 2017 model.