I currently have an hours commute, which I find works quite well for me. It is a little bit unusual though - it is a train journey with no changes, I always get a seat, and I live about a 2 minute walk from the train station, and work about a 2 minute walk from the train station at the other side. The train journey is about 50 minutes.

It's a good period of time to slowly engage and disengage - I do the things that might affect my productivity in the day - read HN, catch up on personal (and sometimes work) email. I sometimes read a book, or message friends.

Everyone's different but this works nicely for me - when I get in from work I tend not to feel the draw of the screen, so my leisure time is less at risk from being sucked into for example reddit, and when I get to work, the period of the day that in the past I have previously lost a lot of productivity to - a 'few minutes' on catching up with the world, 'relevent' tech news etc I've already scratched that itch.

I think it just sort of works with my fairly ill-disciplined personality traits in a way that helps me be productive.

I think much longer though and I would feel I was losing too much of my day. (I'm typically out of the house 07:00-18:00).