The room that racks are kept in is normally 70-75. My snake room is just a spare bedroom and is not tightly climate controlled. However it doesn't get any warmer than 75.
In the back heated model you have to mess with thermostat probe a bit to get it right(you can't put the probe right on the tape, you have to tape it a little bit off next to it) but I finally got it so that the ambient temperature in the back of the bin was 81 and the front of the tank is at about 77.
The back heated works fine, I just don't like seeing my bp's cramming themselves up against the back of the bin for extra heat.