Hey I took my part 1 last week...I surely agree that it was a little tough compared to Crack the NBDE. I will let you know once my score are out weather scores were similar to Crack the NBDE.
From my discussion with about 4-5 friends...final score has always been +/-3 percentile of their Crack the NBDE. Though none of the questions from crack the NBDE appear in the main test...its a good experience, to see where you really stand. Hope this helps...