I'm upto module 7 of the first part, and hopefully sitting the exams in June. THe first 6 or so modules have been hard graft and you are right in that there seems to be a lot to take in and plenty of "Do I really need to know that?" but whether it is relevant or not it has to be learnt. It's funny cos after A level Maths I thought I would never use Sin/Cos/Tan again, and haven't until I started learning about Rhumb Lines and Transport wander... So who knows what you'll end up using!
I have found that some of the subjects have started to repeat themselves and it's mostly revision on some topics, which is also helpfull as they can make sense.
I would also suggest you sign upto the Question bank as well, because it is very helpful to see how questions are asked and what they are looking for, it definately makes you look at the important information more closely.
When you planning on doing the refesher course?