I've noticed that one thing that make me work harder than in an office, is that I feel that I need to earn the trust that my employer gives me. In an office, sometimes I feel that just being there is enough to justify my salary, even if I'm just chatting with colleagues or browsing the web. I discipline myself better when I work remotely.
Another thing that makes a difference for me: I suffer from back pain when sitting in a chair for too long. At my place, I can lie down if needed.
On the downside, I suffer from being far from where decisions are taken, and I sometimes miss important information.