Totally agree, my 8G was set @ 20 and just left to run, only adjusted on really hot or cold days, whereas my 10G needs constant adjustment, almost as if the auto function not working effectively.The air con in the 10g isn't as good as my 8g was either. Mine mists up really easy too and takes way longer to clear.
I've also noticed I have to change temps around more to get it the temp I want. On warm mornings it blows out warm air unless I put it right down to 17 or sometimes as low as it goes. In the 8g I could pretty much leave it on 21 most of the time. If I put the 10g on 21 its always too hot.
Might mention when next visiting the dealers for some mats.