« on: August 13, 2013, 08:03:21 AM »
Depends on what type of photography you do.
I moved from 7d to 5d3 back in Jan. I do mostly street and wildlife.
the loss of reach with FF gets some taking used to, but the noise control, IQ and colour rendition (particularly at high ISO) on 5d3 is sublime compared to 7d. 7d i would rarely shoot over iso1000. Now I shoot up to iso6400 comfortably and sometimes iso12800 with usable shots.
If you are after AI servo mode performance, 5d3 wins hands down vs 6d and 7d.
My keeper rate on 5d3 is way better than 7d (using something like 70-200 2.8 ii). I don't have a 6d but I've tried it and believe its AF system is more akin to the 60d (which I do own) and think its less sophisticated (and my keeper rate is lower) than 5d3.
If you do street 5d3 + 50 1.4 is a nice combo.
Wildlife, I think you will find the loss of reach with FF+300m a bit dissapointing and you'd probably want to get a 400mm to compensate.
5d3 + 24-105 L is a wonderful combo, but I gave it a miss because I own primes @ 24, 35, 50 and 85m
5d3+ 100 L is a fantastic combo. 100mm macro makes more sense to me as a focal length than on crop (although I can't put my finger on what; perhaps its just the field of view difference).
my 2 cents:
If you're after good AI servo performance; get 5d3. If you're after FF on a budget and don't care for servo, get 6d.