Looked after 2 dogs belonging to friends on seperate occasions this month; first one was fab in the house, fab off the lead, but very, very reactive to dogs on the lead - pulled like a tank (very large dog) and barked his head off on his back legs every time he saw a dog. Also very barky at every little noise in the house. Second dog (this weekend) has had no basic training whatsoever, but is a naturally calm dog when out and is not even vaguely interested in other dogs, but doesn't understand "no", has been allowed to run all over furniture (I do not have dogs in bed etc - probably in the minority here!), and has cocked his leg up every single available surface in the house whilst whining and being underfoot the whole time.
I whinge about my girl sometimes, as she's a bit reactive to other dogs and can be a tad unpredictable around strange ones when out, but in the house, I barely know I've got her. She tends to pod off somewhere comfy and sleep, only barks when the postie comes, walks lovely on the lead and her recall when no dogs are around is 100%. Made me realise that I'm actually very lucky to have such a good dog and I will endeavour to not complain about her very few shortcomings in future 