This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
In my five Enthuware exams, I got between 40% and 70% correct answers. The day before the exam I scored 63% in Sun's assesment test.
The Enthuware exams are worth every penny (or Danish kroner, in this case) and I would highly recommend buying them or something equivalent. There are, however, some mistakes in their questions as well as their answers so read their answers carefully and be sceptical. Consult the specs when in doubt.
I want to recommend NOT reading Mikalai Zaikin's guide. The English is quite bad in places, sentences are missing words in many places and e.g. tables are missing data. If I had to do it over, I would definitely recommend spending the time I spent on that reading the specs instead.
So, obviously I think the real exam was quite a bit easier than Enthuware's exams and MUCH easier than Sun's assesment so don't panic if you don't score 90%+ on those!