I found this study a while back that really seemed to explain what I see at home too- http://books.google.com/books?id=UaCNtle9my0C&pg=PA4&lpg=PA4&dq=Some+children+under+some+conditions:+TV+and+the+high+potential+kid&source=bl&ots=_FRUxhuuZ-&sig=h32srjUr23GUxJkir_Wlfgfc9XE&hl=en&ei=VyoES-qOLInWsQOoiZHGDg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CAgQ6AEwAA#v=onepage&q=&f=false
For us, I've basically stopped worrying about screen time. I have an only child who is wide awake and ready to take on the world at 5:30am. There's pretty much NO way I'm getting up that early. He gets up, watches TV and has breakfast on his own until about 7am. Then DH and I drink coffee and read the paper with him while he does his homework. It works well for us. After school, he usually watches another half hour of TV, plays a computer game (always educational- TimezAttack, Carmen SanDiego, Zoombinis etc) and sometimes does Aleks too. On a school day, it's not uncommon for him to have 2 hours of screen time. On the weekends, he will play Wii or DS and will likely have 3 hours a day.
We also get out and go for a family walk, have dinner together every night, read together for at least 30-45 min every night. It's about balance, not specific minutes for me.
