Not to play devil's advocate, but we use Alife thermostats (nearly identical to that ESU model) and have had great success with them as we regularly check belly temps with a temp gun in both the cool and warm hides as well as regular spots in the rest of the enclosure - the temps are always spot on.

We want to move up to Herpstat/Helix level therms when we eventually need to move the girls into larger cages, but the Alifes have been good to us so far.