It saved me a fortune but it was a pain in the arse at times. Trains round her can't always be relied on, so I'd have to get one an hour earlier than the one I really needed just in case it was cancelled etc (so that I'd have time to make alternative plans - I got stung a few times with cancelled and delayed trains and got sick of taking the risk.)
This'd mean getting in at least an hour before my first thing of the day if the trains ran well, which meant a lot of waiting around.
Also meant I had to get in earlier for exams and stuff. As KDB says, time is valuable and having to be up and out two hours before everyone else can be a bit grim.