I am coming to the end of of the full-time course at GCNS now and so am biased when I recommend it. I work 20hrs per week so still pull in some cash - i guess it depends how flexible your employer is if this is possible. The benefit this gives is 1. that you are effectivley forced to study when listening to lectures - no motivation probs there then, and 2. you go to work knackered instead of trying to study in that state after a day at the office.
I have also heard of a 10% eventual success rate for distance learners due to the difficulties involved.
Personally, even in the current climate, I think that the full time route is more advantageous both for your learning and sanity!