Hey All, so I have a Tokina 12-24 f4 for an UWA that I used primarily for action sports shots and anytime I really needed to get wide when my primary body was a 50d. Now that I use a 5d MKii primarily I'm wondering if I should ditch the tokina for the 17-40.. I do weddings/portraits/music photography and still some action sports stuff for fun.. I do use my 50d as a backup and sometimes a second body when swapping lenses just isn't in the cards (I use alot of primes), so I'm wondering if I should ditch the 12-24 and buy the 17-40 to use on the 5d... any thoughts??