Is the 24-120 F worth it over 24-85MM VR?

...unless you need the extra reach. The 24-120 suffers vignetting and CA as well, so if those are your two main issues, you won't be improving much of anything but you'll be out $1,000. You'll also lose half a stop on the wide end and gain half a stop on the telephoto end. Doesn't seem like the best of all trade-ups to me...