Like Bob my experience is limited. I have a small improvement in solar rejection since I painted my roof white. I also tinted my over abundant windows.
I'd also like to hear from some of those who have polished.
My gut feeling is that we're up against inadequite insulation and no thermal break between outer skin and interior fixtures.
Gain or loss should be minimal, but shiney is all good!
1984 28' Funeral Coach
Former Rolling Showroom & PuttLab (now party bus)
"I'm not an expert. But I did sleep in an Airstream last night."