It seems to me RTTs are growing in popularity in the South. Here in ATL, I've seen more and more every year.
I've thought about one (and will likely get one at some point) but here's what's held me back so far:
1. I camp all over the Southeast so in some areas you're much closer to the heaviest part of storms coming out of the Gulf and even far inland the wind and amount of water can hellacious. And when I've made up my mind to go adventuring, I'm hellbent on going. And if you can weather through the storm, the weather in the aftermath is typically beautiful as the system moves away. So I've wondered how well these tents fair in our storms down here. I've read what manufacturers say about the winds they've tested in, but there have been historically so few around here, I've not had a chance to talk to many owners about their experience.
2. Being in ATL I'm either headed to the coast or to the mountains. In the mountains, and again I'll go camping in storms, I've had ground tents damaged by falling branches. The more expensive RTT getting ripped would suck. Whereas replacing my REI or whatever backpacking tent I have doesn't seem as big of a deal.
Finally, I hear ya on the heat thing. Something you may want to try at some point, hammock camping. I have a Hennessey Hammock with mosquito netting. I've woken up cold in the middle of a GA summer in mine. It packs down real small too.
Again, I'll likely get a RTT at some point if for no other reason it's about the only camping gear I have NOT owned. And there are so many good applications for one. I just include the above as things to consider and hopefully help think through it.