Ok, first, questions on variances on actual exam are definitely not as difficult as on software. I overstufied variances; thought it was my weak link and ended up thinking that it was much easier than IT on exam...
Second, remember how Olinto said: make variance your Friday date? I did that. Spent whole day listening to his explanation of that one page on CD... Finally it came to me. With struggle, but it did. And I used Wiley book as well.
That was sufficient for doing actual exam problems, BUT still not sufficient for Becker homework problems - they were just too complex.
Now, maybe other people will have different opinion, but I think if you can do basic variance problems and have problems with huge wordy ones - you are OK for the exam.
Just my opinion, though.
BEC (82), AUD (86), FARE (75) => Becker 2009
REG (74),(74),(83) => Yaeger HS & Audio