I have a HD tv in the sitting room and a SD tv in my room so basicly I always try to play on the HD but I will only get about 2 hours max before some1 wants to watch something so then I will try not to but end up playing in my room :P .
I personally think there is a big difference but the good thing is that whenever I go from my room to the HD tv I always get amazed at the graphics, it’s like it got an upgrade and I get a re-falling in love feeling xD .