Re: Opinions on Bristol gs CBT.
What the CBT lacks in margin notes, it makes up for in animations etc...which really helps when you have been struggling with the written text trying to understand something, then kick yourself for being so stupid when the animation makes it so blindingly obvious.
I found using the CBT as the initial training source, then the manuals for revision, worked well for me.
As someone else has commented, the groundschool is superb. Hard work, but well worthwhile.