#15 is simple and easy to see. Would be very easy to see on a website or brochure.
I was really torn about #13. That is one that you either love or hate. While I liked it, the other people in the office didn't. Had to pass on that one.
II did take the time to review the website, the site already has clean fresh look to it so a simplifies urban style without eye candy effects is best suited to a brand identity...the current logo has eye-candy and it looks out of place on the site.
I can understand why #13 does not appeal. the thing about crowd-sourcing sites is if I do not do it someone else will and it may just win...but not in this case. #13 is a spin on the original company logo.