While I haven't used Google Glass yet, I can't imagine being productive (or being able to relax) while using it. I usually try to disable as many potential distractions as possible when working. I don't have mail notifications, I don't have chat notifications, I don't even have a clock that shows the time on my desktop. I'm way more productive when handling those things on my own schedule (e.g., batched handling of email every few hours).
Using something like Google Glass would probably drive me crazy. I wonder how (and if) Google Glass users can get productive work done. Do you wear Glass while you do things such as coding?