I've been doing it since New Year. It was a bit daunting at first but once you put aside an hour (or 2 if you walk back) it just becomes part of the day.
It gets easier and it's a hell of a lot less stressful than being stuck in a mobile zoo (the 122) full of screaming schoolkids and morons blaring out c**p on their mobile phones.
An added bonus - I managed to lose a stone in the first 6 weeks too.