Hi, i have recently cleared the exam. I haven't used any of the commercial exams.Anand Chawla's exam is almost similar to the real one. An 80% in that exam can be considered good score. Mika Hirvasoja's exam is also good. Eduardo Cobian's exam is very tricky, and the trick factor in real exam is not that high.
I have heard lot of people saying that JwebPlus is good but i haven't tried it.
Hope this helps