Good cheap insurance to have the second one, whether you need it or not. If your camping in the summer, and you have only one, and it decides to quit on you, game over, you're going home or calling the nearest RV place. If you have 2, you have a spare per say and can manage. We've always had 2 on the units that offered it. Well worth losing 100 Lbs of carrying capacity to have the cooling capacity available. In the summer, we almost always use both in the hot, humid Louisiana weather. If they offered 3, I'd have 3.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.