I am on a the JAR modular zero to frozen atpl route at a well known flying school. For the first two modules (which was done in Florida, USA) I had to complete the PPL, multi rating , night rating and 150hrs Total time) in about 8 weeks.
This time included all the studying for the exams and flying. I found Air Law and met pretty hsard but a/c general, human perf., and the rest pretty easy.
Navigation was pretty tricky because it is all chart work - which would be fine if I had been flying in the UK before but having first flown in the USA using FAA charts it was a little tricky.
The confuser is a definate must - but read the books first and use it as an aid rather than learn the answers.
Good luck