Almost a year in, here are my thoughts.
My back pain is gone 98% of the time. This time last year I woke up everyday to pain. It is so nice to be able to get up ready to go, especially with small kids. My wife's back pain is also gone. She is pregnant now in the last trimester and she is a lot more comfortable this time around than last.
Sleeping hot. Doesn't happen. In fact I sweat significantly less on the Casper than with my old Simmons mattress. Used to wake up in the summer to a pool around me, didn't happen at all this summer. This mattress breathes so well because of the latex layer on top which is exactly why we wanted to try it.
Sex is every bit as good as on my old mattress, see the pregnant wife comment. We gave it the old college try and had no problems changing positions or getting stuck or anything.
Sleep quality is great. I don't have any metrics to prove I sleep better but I definitely toss and turn less. I primarily sleep on my back but my wife is a side and stomach sleeper and she doesn't have any complaints.
Absolutely 10/10. We will be purchasing again when it is time for a new one and may get one for our guest room soon.