I did the CBT, 125 route, rode the 125 for around 3 months before I was sick of it.
I then did 2 days training before doing full licence.
I would reccomend the doing direct access, the level of training I had compared to CBT was far superior. I feel a much better and safer rider on my bigger bike (ducati monster so nothing crazy!) than I ever did after a rushed 1 day CBT training.
If you in south west then Chris at MTS training, okehampton is awesome!
Who cares if bike is faster / slower, its better!