Ah, the classic debate of part time vs full time again. Sigh..

I think it's depend on people to people. I personally know that i'm not the "part-time-and-do-it-safely" kind of person. I get too comfortable.

I function much better as soon as i burn off my ship and jump off the cliff. Somehow, that's how my survival instinct works. That's how i signed up for 1/2 marathon and full marathon while i haven't been able to run one (and, of course, after that i became much more discipline in training and eventually finished).

Again, it depends on your personality.