Yeah, I got a B6 for SOR1, so I think aligning would be even tighter than SOR2. I didn't check but I'm certain it was around 44/50 for 2011 (although can be as low as 42/43 depending on the paper and cohort).
SOR is pretty easy though. Nothing technically challenging, just a bit to remember. Do past papers as Section 2 is usually similar (although for 2011, it was a little different in the types of questions), and Section 1 is MC so that can be prepared via the online MC tester. Section 3 and Section 4 (for SOR2) can also be prepared through reading material and answering past questions.
It's probably the easiest to study for as there is only so much BOS can do to make questions different from the previous year.