When we had our 33' Class A, it had two 15k btu A/C's. It was an open floor plan with no wall at the rear queen bed. We found that even with 2 units we still were hot if the temps exceeded 100 f. Once when we were in Phoenix during the middle of summer with temps about 115+, the units couldn't keep up.
Now that we live in the desert full time, our bodies are more conditioned to the warmer climate. Anything below 60-65 f and I'm putting on sweats. Our temps just recently dropped below 100 during the day for the first time since spring. The newscasts here say it is a cool 90-95 this week. Love it!
When we buy our TT next spring, I am going to order it with 2 a/c units if it's an option on the model we settle on buying.
Hope this helps!