Wbryce,
Hi, glad you could join us. I used Trevor Thom vol. 5 and the airquiz tests. The airquiz tests relate quite closely to the real exam in terms of difficulty and makeup so they are a very good indicator.
How true it is I don't know, but an instructor recently told me that the Trevor Thom series is now the baseline that the CAA use to set the exams from.
I'm not a big fan of the confuser series of books, but then I didn't need to use them. The IMC exam is an extension of your visual nav, flight planning, airlaw and met from your existing PPL. However, the joy is that the major bulk of the content relates quite closely to what you need to be able to do.
ie. Plan a flight including logcard and fuel useage.
Awareness of the effects of met on your planned flight
How to read and get information from an approach plate
What the instrument flight rules are and application of them.
Basically if it's not in Thom vol. 5, then it was already in your previous PPL exams. Oh and a lot of the information is easier to remember when you have some training to relate it to. I read Vol. 5 before I got heaviliy into the airborne work and it could have been the history of art in the Falkland Islands I was reading about. I just couldn't remember it that easily. After a few hours in the air it fell into place more easily.
Regards
Obs cop