Looking for feedback from those who have both the 1DIV and 5DIII

[canon816]

I have a 1DIV and a 5DII.  My 1DIV is a fantastic camera and performs like a champ in every area except high ISO IQ.  I am happy with images through ISO 1600.  Feel that Images are Usable at ISO 2500, however at 3200 and above the IQ really drops off fast. 

My 5DII produces images through ISO 3200 and 4000 that I am consistently happy with, however the performance of the camera leaves something to be desired.  AF system is horrible on dynamic subjects and FPS is certainly lacking.

The 5DIII seems like a nice replacement for my 1DIV with a nice blend of superior image quality at high ISO and many "pro body" features. 

This is a question only for those of you who have or have had both of these cameras....

What are your thoughts on replacing a 1DIV with a 5DIII?

... please don't post if you don't have both of these cameras.  I'm looking for actual hands on comparison, not conjecture from folks who have read about it. 

Thank you.

[Mt Spokane Photography]

I replaced my 5D MK III with a 1D MK IV and re-purchased a 5D MK II.
It all comes down to which features you value.
If you like AF at f/8, a focus point that lights up, etc  the 1D MK IV might work better for you.

[canon816]

I replaced my 5D MK III with a 1D MK IV and re-purchased a 5D MK II.
It all comes down to which features you value.
If you like AF at f/8, a focus point that lights up, etc  the 1D MK IV might work better for you.

Thanks for responding.  Were there any reasons that you really didn't like the 5DIII other then the two you mentioned?

I don't need f/8 focus as I generally use fast primes and don't like the results of a 2x converter.

Any other reasons you made the big decision you did?  Thx...

[Mt Spokane Photography]

I replaced my 5D MK III with a 1D MK IV and re-purchased a 5D MK II.
It all comes down to which features you value.
If you like AF at f/8, a focus point that lights up, etc  the 1D MK IV might work better for you.

Thanks for responding.  Were there any reasons that you really didn't like the 5DIII other then the two you mentioned?

I don't need f/8 focus as I generally use fast primes and don't like the results of a 2x converter.

Any other reasons you made the big decision you did?  Thx...

If you are shooting wildlife, the 1.3 crop and the f/8 allows you to put a TC on.  A 400mm f/5.6 lens plus a 1.4 TC gives you a 728mm equivalent. This is much less expensive than a 800mm lens, and for me, much easier to use.
I also do low light theater photography, and the inability to see the AF point in low light makes the camera almost useless in that situation.  The 1D MK IV is not a good in low light, but you can see to focus, which actually translates into more keepers.  I'll likely use my 5D MK II in low light, its center point AF in low light is supurb and fast.