I am pretty sure the Nest can present you with stats about when and how long your system was commanded on. What about the other products? What other smart thermostats have this feature?
Thanks

 

Nest does have logging ability, but I see it as a bit incomplete and quite simplistic. Nest doesn't have an outdoor sensor so it can't accurately log outdoor humidity/temperature. Instead it uses info downloaded from your nearest weather station.

I found that the best logging system is on the Honeywell Prestige 2 IAQ system. It runs 3 different logs.
A performance log which logs all the data you can think of.. indoor/outdoor humidity, temp. Delta T (difference between your furnace inlet and outlet temps), running time for each furnace stage... etc. it does a log entry anytime the furnace comes on. It also groups the logging by day, week , or month.

The alert log, which logs any alerts that you may get, filter change alerts, high water alerts, Delta T alerts....

The change log, which logs ANY change you make on the furnace, change in temp or humidity settings, set up changes... etc.

The IAQ spits out some pretty detailed logs that I have found hard to beat, and they all can be downloaded to stick in an excell format so you can view it either on the stat itself or on your computer.

Some screen shots of the performance log. This sheet is just for the cool stage 1 on an hourly basis. Stage 2 is a whole other sheet (I have a 2 stage heat pump):


Had to split this in 1/2. The top one is left side, the bottom is right;

 

Thanks Bob,
Looks pretty need. I have two,heat pumps in a two story house and I'm basically trying to make sure ai set the two thermostats correctly in relation to eachother so one is now being over tasked.
Looks like that one would be able to give me the required data. Thanks