I have/had all the cameras that you mention. If you don't have a lot invested in Canon glass, I would buy a D700 simply because the high ISO performance is so much better than either the 1DM3 or 5DII. The D700 does not have the ulgy banding that my 5DII has at high ISO. Unless you intend to use a lot of flash, ISO performance is important for kid shots as many will be indoors with lighting that is less than ideal. The AF performance of the D700 is more than adequate for your needs. I sold my D700 and I am regretting it. It is a great all around camera.
My biggest beef with Canon is that I can't get a good "walk around lens". I tried several copies of the 24-70mm L and could not get a good one. Then I ordered a used 28-70mm in EX shape and this was just horrible. I tried a copy of the 24-105mm and did not like the edge performance. The new Canon 24-70 is far more than I will spend.
Never had this problem with Nikon. My copy of the Nikon version of the 24-70mm was tack sharp. I may have to add a D700 back to my camera mix just because I have given up on Canon in this FL range. Other than that I am very happy with my Canon lenses, particularly with the 135L.
Hi,
I had a 1DMKIII for four years. At a given moment, I had both a 5DMKII and a 1DMKIII in my bag.
I am not a pro, so I ended up using one over the other, and the 5DMKII produces better files, that simple. If ultimate quality is your concern, the decision is easy. When I bought the 5DMKII, the 1DMKIII was used when I needed speed. ( I must admit that now I travel a bit scared of breaking my now only body on the first day)
The screen of the 5DMKII is MUCH, MUCH better than the 1DMKIII. Not only you can judge focus on the 5dMKII screen, but manual focus is also much easier. I shoot some MF lenses, and liveview on the 5DMKII is a tool whereas on the 1DMKIII is a toy in comparison
Notwithstanding the 5D MKII produces better CR2 files, the feel of a 1D series is just amazing, wish my 5DMKII were encased in that body. ( that camera currently exists, but it costs 6,500$)
For portraiture and landscape photography FF cameras are much better. However, if you plan to shoot action, the 1D is far better
Many people will tell you that both cameras complement each other, and it's true. The new 1DX is a dream come true, the one and only camera suited for anything.
