It does depend on what you’re doing when you’re working and whether being at home will mean not hearing another human voice all day (Jeremy Kyle doesn’t count). I spend big chunks of every day on teleconferences so I’ve done enough talking outside of them. I’ve also got the box-room set up as an office which helps a lot with discipline.
I don’t actually work with anyone in the same office as me so I’ve often wondered how long it would take for someone to notice if I moved abroad without saying anything. I reckon so long as I kept appearing online at the right times it could be some weeks…
EDIT: to answer the original question – if I don’t spend time commuting there’s at least a chance I’ll get an extra ride in. for a while when work was less manic I used to go bouldering (indoors) at lunch. Overall, for me, it’s great. Might not be so good if I had kids to be distracting, mind.