I've been using the Big Apple thermostat for about a month now and it seems to work OK. It keeps a fairly constant temperature. At least within a degree, at worst. One thing to note: The instructions say not to use it with anything less than a 25 watt device. Although I tried it with a little 8 watt UTH and it worked.
I haven't tried the night drop feature.
I don't like the fact that it's not digital. You have to tinker with it to get the temperature set at the right point. But the dial is fairly accurate.
And it makes a buzzing noise. It's not too loud. You have to be within a couple feet of it to hear it.
I haven't had any experience with any other thermostats, but I'd like to hear what other people think. I think my next one will be digital.