After years of contemplating the 16-35 II, I finally pulled the trigger on it with B&H... Deal was just so tempting! The double dip rebate for $1329 plus the last day for Discover 5% cashback and B&H 2% (-$78 and $-30 from $1529) takes my total to about $1220... Not to mention the free overnight shipping (which I think will be delivered tomorrow via UPS which is air only delivery tomorrow). All the stars aligned to get my GAS roarin'!
I have been a huge fan of the 17-40... I simply love it! I understand the 16-35 II will gain me almost no real IQ difference other than extreme corners, but the f/2.8 is really desired now with my few gigs in the summer doing event photography (low light, stage type lighting). The f/4 was pushing it, although it did OK in those situations... I look forward to having 16mm at f/2.8 though. I debated the 14L II, but for my shooting it is just too limiting (plus, I would rather just pick up another Rokinon 14mm for that!).
Hoping I don't regret the $600 upgrade costs... I don't think I will, as long as I get a good copy (knowing my luck, something will be broken or decentered). But my current 17-40 is just so darn good, I worry... Its perfectly centered, sharp wide open end to end, etc... I just hope the 16-35 II is just as solid in performance!
Hoping for the best!