(not my keyboard, but much like my cat)
I get SO MUCH MORE done when I am in the comfort of my own apartment and no one is talking around me. One of my coworkers says he doesn't like to work at home because it doesn't feel like he gets separate space, but I feel just the opposite. I think this is probably an introvert thing. I find ambient noise distracting when I can't control it. In the office I wear headphones and play music, but I can still hear the conversations going on near my desk, which is frustrating.
Sunlight from the street comes in through the windows, which doesn't happen in our office. The cats like it, and so do I.
My sleep schedule is better if I get to wake up half an hour to an hour later, and sometimes I actually eat breakfast rather than stumbling out the door. Today I nursed a mug of cream of wheat through the morning and fried up some eggs for a quick lunch.
My transportation costs would go way down if I worked from home, too (not to mention the hassle of being late to work or crammed up against disgruntled commuters).
Plus there's the added benefit of being able to toss a load of laundry in the dryer or wash a sinkful of dishes during my break. Maybe take a little lunchtime walk. I did that today once the sun came out, and it was GREAT to stretch my legs. (Sometimes I do this when I'm in the office, too.)
On the downside: missing out on free snacks and weekly catered lunches; having only one monitor; that darn trackpad on the laptop instead of a proper mouse. All supremely manageable. It's really not much of a contest!