Although my group euphemistically call it "Shirking from home" I'd echo the sentiments that a day or two with no distractions allows you to get a whole lot done.

Which raises a serious question about the modern work place. Although an open plan office is great for collaboration it is terrible for getting into the zone.  Slack, Skype for business etc sound such good ideas but for every 10 minutes they save I bet they take up an hour.