I come in at around 11 45 every day and work until 7 with couple of 15 minute breaks for ping pong. No loss in productivity and extremely satisfied with commute

I come in at around 11 45 every day and work until 7 with couple of 15 minute breaks for ping pong. No loss in productivity and extremely satisfied with commute(DC metro). But I make sure, I check my emails and respond at around 930 am, if some one needs me.