I have a Visitherm Deluxe in my 75, no complaints at all, and adjusting the temp is easy. However according to the dial it's 77, the actual temp is @ 79. Not too far off..
I use a thermometer (alcohol) to get the reading and adjust it by that. but once it's set, you never have to touch it again.
120 Gal SW, 150lbs Prem. Fiji, 23Gal Sump, 2x250w 15K MH, 4x65w Actinic
3 x Halichoeres Chrysus (1 surfed), 3 x Nemateleotris magnifica, 1 x Centropyge bicolor, 11 x Scarlet Hermits, 6 x Zebra Hermits, 40 x Astrea Snails, 6 x Nassarius Snails, 3 x Cerith Snails