I have a Hydrofarm as well, it seems to work reliably but there's a couple things I don't like about it... One, it only has one plug, so you can only regulate one device at a time. It also has a variance of 2'F before it kicks in. Meaning if you set it at 96'F, it won't kick on until it reads 94'F. Maybe not a big deal, but I'd like something a little more consistent. It also makes a loud "CLICK!" when it turns on.
The other one I have is this one from Zoomed:
http://www.amazon.com/Zoo-Med-ReptiT...ile+thermostat
It's annoying that it doesn't have a temperature setting (What exactly is a gradient supposed to tell me? Really?) so you have to keep a close eye on it when you set it up and match it with a reliable thermometer next to the probe. I use it to regulate the lamps since it can regulate two devices at once, and has a narrower on/off window. I.e. if you calibrate it to 84'F then if it drops below 84'F within half a degree it turns on.