I've had a $25 Repti Temp 500R for almost a year and 0 issues. Yeah its a little hard to set at first but get it close once and done. And yeah you would have to run the dimmer after the tstat with the tstat being at max power and the dimmer turning it down to whatever temp you needed it to be at.

Also plenty of other ppl with the 500R for years and no issues. I'd never personally use an on/off style on a rack or anything like some do but for a single animal in a viv they're fine.