^^^^^^^^^^^^^ What jcussen says ^^^^^^^^^^^^
In AZ my (brand new/replacement) 15K unit doesn't even come close. After the sun goes down it is a lot better, of course. Most folks figure their coach will be about 20 degrees cooler inside than the ambient temperature...... better in the shade. Even then you sometimes have to start out early in the day to "get a run at it".
I "think" I read in previous posts that with the 2 ACs you have 22,000 BTU's (11,000 each.) That way you can run both ACs on your 30 amp coach without shutting almost everything else off. It is a GREAT option, IMHO ....... wish more manufacturers offered it. I don't believe you will ever regret going with the 2 AC configuration. 50 percent more cooling is a really good thing.
Just my $.02, of course.
Ed Sievers, Denver, CO
07 WBGO Outlook 31C; Toad: '16 Soul with 6-spd DIY
"Be the person you needed when you were younger"