Your design is the best of the bunch so far, though I'll be honest that it hasn't grabbed my heart (not sure how the client will respond.) Check out my further feedback on the main project page in case you want to take any further stabs. Entry 3 was too stereotypical to keep in the pile; Entry 4 looked a bit too much like a luxury brand purse logo for our tastes. ;)
Regarding #57, I like the design, you have a good style for what we are hoping to achieve - the only concern is that it highlights the number 4 a bit TOO much. See my general comments posted today on the contest page about the #4 vs. other imagery.