All great questions, and I can appreciate the concerns.
Have you ever used an "On Off" thermostat with a light? It's pretty fricking annoying, and the "lesser" quality stat is keeping perfect temps, if it was not I'd change it immediately, however for $31. and spot on temps there is not a need, which is the point of the thread. It's sort of pointless to post a thread about something that does a crappy job keeping UTH temps.
The UTH has been as consistent with this as it was with the Herpstat which says a lot about the inexpensive, but not cheap unit. I'm sure it will wear out quicker, but it fails in the OFF position and without it, temps in the room and ambient temps in the cage are good enough where there would be no urgent situation.
Inexpensive does not mean it does not work by any means. The Hydrofarm was designed for heat mats. The particular setup I have is a glass tank, and I prefer a light, not on a dimmer to use for ambient temps.
At certain times the light is completely out because the Herpstat does such a great job controlling the light and during the "night drop" I don't need to go down and dim it when I travel or am working late. The hot spot can stay constant, but I drop ambient temps in all of my cages at night. Not part of the Hydrofarm's design.
Personally I don't see an advantage to a lamp with a dimmer switch when I have two functioning thermostats.
IF I wanted to spend more $$, I'd restructure the top of the cage, dump the light and buy a third Pro-Products RHP and control the whole tank with the Herpstat-I. My boa and carpet cages function excellent with RHP's, but to get usage out of the glass cage I went this route.
Why not use a $31 stat that works?? Makes sense to me.