Just thought I would post my experience, since I obsessively checked this thread for advice on studying and towards the end to try and predict my score. I am an average student. Shelf exams were in the 70's mostly, don't remember exact scores.
Step 1: 230
Step 2: 262
UW avg = 70% (completed all UW question)
NBME 2 = 252 (taken two weeks before test)
I am obviously thrilled with my improvement. I studied for 4 weeks and used FA, secrets, and UW. I read through FA in one week and did corresponding UW blocks for the subject that I had just read. I'll admit, I annotated UW into my FA the whole time (even two days before the test, I was still fursiously taking notes). This was not as helpful as when we did it for step 1, but I think the simple act of writing things down helped some.
Secrets - awesome book! I really wish I'd read this over again a few times, it's so easy to read and the material sticks better than FA in my opinion.
UW was a great source. However whenever I did question blocks, I felt cluless. There were so many times when I didn't even know what the question was asking but I somehow managed to get a decent percentage. This is how I felt with the NBME 2 and the real test. Clueless for many, many questions, but it turned out ok.
It has been said several times, and I'll say it again the real test is loooong, and tough. What made it worse was that during blocks, a question would remind me of previous question from another block and I would suddenly realize that I had gotten it wrong. This just contributed to my anxiety.
One other thing, I made sure to take a practice test at least two weeks before the test. For step 1, I took one two days before and I just freaked out because I wasn't even close to getting what I had wanted. So for those of you with test anxiety, keep a safe distance between the practice test and the real thing.
Hope this helps! And good luck to everyone =)