I'm currently about half way through my CPL theory. I'm attending a class at nights part time. We use Ruth King in class, but I find that to be a bit 'this is how you pass', but benificial none the less. I resorted to reading TT as well. It gives me a different view of things, (a bit more indepth).
in rgds to Cyber exams:
Nav is identical to TT and RK. I cleaned house on that one. Aerodynamics is fairly similar, but with a stronger emphisis on wake turbulence, so study up a bit on that one. They ask very confusing questions. Two guys in my class failed, not because they didn't know their stuff, but because of the way the questions are asked. You will need to do some wider reading re Wake turb. Performance is pretty much identical to TT/RK.
The trouble with the theory books/classes at the moment is that the system has changed, so the examinations are a bit more indepth than they used to be.
I would suggest a theory class, as there will be people there from all differet backgrounds/professions who will excell in cirtain subjects and help you out and vice versa.
Don't stress about it, if you can do TT, then you'll be fine.
fnb