Hi,
I use that brand - mainly because for years and years that was the only type there was available.
I have never used the twin channel one but I do have a dimming day/night, a pulse proportional day/night and two normal temp on/ off types.
What I did like was the day/night trigger is by plugging in another power lead and setting it on a timer - the night eye types are of no use to me owing to my messed up usage patterns of the room.
They have lasted me quite well it has to be said and I have only ever had a couple fo failures in over 12 years or so - but when they failed with me they failed full on and cooked the animals involved.
On the one occasion the failure was within warranty it was repaired quickly and they even repaired the probe which was a bit scuffed.
The microclimate ones have the protection feature on some models so I plan on buying one of those next to try out - but they use the night eye system so they are essentially useless to me in regards to that function.
There are also "lucky reptile" digital thermostats that look very intresting if I can find the feature set I want.
I assume you have checked to make sure the voltages match? I don't know what you use but we are on 240V 50-60 Hz.
Where did you find information about sending back habistat thermostats - any I have had the return information was to England so you have me all curious now.
dr del