I have slept in a cloudburst (the older model tarptent), and I own a lunar solo. I can't give you a solid opinion on hot and sticky climates because I don't hike in them However, ventilation being a concern for me, both tents vent very well when pitched properly, and if you pitch them high you get plenty of air in both. I personally like the lunar solo side entry, but it's a matter of personal preference, both are very good tents. One thing possibly in favour of the tarptent in hot weather is a slightly lighter color, and the ability to set it up as a tunnel shotgun-house style with one end *facing* the wind to get breeze through the shelter.

Having said that I don't think you'll find a lot of difference, and either way, I don't think you can make a bad choice between those two, so don't sweat it. pick one and go with it, spend your time worrying about how to get out more rather than worrying about which tent