I love my solid latex mattress. It's the second one I've had (first went with the ex in the split), same manufacturer (a now defunct Aussie brand) but totally different.
The original one was about 12" deep with a topper. Fabulous mattress all up - exceedingly comfortable, and for the first time in forever I never woke up with an aching back. It did retain heat though.
The current one is only about 6" deep, and unfortunately about 6" too small lengthwise for the bed base. It's comfortable, no aches and pains the next morning, and yes, it also retains heat. Not that I mind, it gets a bit chilly down here in the southern reaches of Tasmania.
The manufacturer recommends turning the mattress (not flipping) every couple of years, ie head to bottom.
One thing to be aware of, they are heavy. Very, very heavy. Turning them is a two person job. I've managed to do mine on my own with lots of pulling, dragging, and bellyaching - well, the dog did help by laying on it while I was trying to turn it, but she wasn't really much help.
They also need a firm base, such as slats or similar, to avoid too much sag.