I just took Becker. I REG (7/2), and it was not what I expected at all. Without getting into specifics or anything, I had stuff on my REG exam that was not covered whatsoever by Becker I was stunned when I walked out. I felt very well prepared, like I had an excellent grasp on the materials in the review course. Then, I took the test.
I didn't use a single mnemonic (there were about 20 of them I had memorized/thought were extremely useful), and had some of the supposedly “heavily tested” areas in Becker not tested at all. Literally, I could list 5-6 things that were covered extensively (multiple pages) in the review program that were not covered on the exam. It was frustrating; I felt “ok” after the first testlet, and the second one was harder, and the third wasn't a cakewalk either. I can only guess that I got a lot of new material.
The simulations– definitely not what I expected/practiced, and I just tried to make sure I wrote well on both communication sections and at the very least found the research/authoritative guidance questions. So for those of you preparing for REG, I hope your test goes better than mine!