I use a thermostat with my meru on the basking lamp as an extra precaution against overheating since the species requires cooler temps for basking and ambient. Overall, I've been very happy with it, but I do have a single concern that as the enclosure heats up during the day there won't be enough basking time for the little guy because the thermostat will keep the lamp off. Fortunately this doesn't seem to have been an issue yet because he likes to bask in the mornings from my observations and only periodically the rest of the day.
Also I should mention I'm using a proportional thermostat, which I believe are far superior to normal thermostats because they're not as harsh on your lighting hardware. If you decide to use a thermostat, you'll also need a surge protector (a small single plug one is what I use) to protect whatever it controls from the on/off surges that they invariably produce. I know this is true for lights because I blew out 3 bulbs before realizing what was happening, but I'm not sure of its necessity for other heating implements. A friend of mine that keeps corn snakes uses the exact same thermostat from Big Apple Herps without a surge protector on a ceramic heat emitter...
Hope this info helps!