I'm probably working harder from home than when I was in the office. The flip side is that I gain an extra 2 hours from not commuting. This is time that I can use for myself - such as sleeping until 8:30, instead of leaving to go to the office at that time.
Also, what with restricted socialising in the pub etc. I've more free evenings, so if I'm busy and want to work later then I can. Fortunately I've an interested job so don't mind doing that on occasion. I wouldn't want to make a habit of it though.