There are lens review websites that take lots of measurements and I find these a useful resource for comparing lenses in a more objective way... two I often consult are
http://www.photozone.de/fuji_x
http://www.lenstip.com/index.html?test=obiektywu&producent=66&model=&typ=0&moc=0&przetest=1&szukaj=Search
They typically measure sharpness, vignetting, distortion and chromatic aberration, although I also appreciate lenstip's illustration of coma in the corners.
I recently tried to compare the 10-24 with the 14 and also with the 18-55. Each lens has pros and cons but I think the 10-24 at 14 compares well with the prime at f/4, although my important criteria might not be the same as someone elses...