[Kombisaurus]

Well... if I spent less time posting on forums and paid closer attention to my phone.. I would have noticed the missed call I received from the camera shop saying they had a 5D3 body waiting for me! woohoo..

I picked it up just before the store closed and have only had a brief play with it so far (I had to go out tonight).
First impressions are great. I love the AF features and it locks onto subjects in very dim light. I must admit I was expecting the AF to be a little quicker... it's certainly no slouch, but it's no 1D either. It might have the AF abilities of the 1DX, but it seems to all happen at the speed of the 7D (which is perfectly fine, but doesn't blow your socks off). It's brilliant for weddings, portraits, travel, street, etc... And it's perfectly adequate for sports, but I can still see a market for the 1D-X for the dedicated sports photographer. But the 5D3 is easily the best all-purpose camera I've ever used, and it's effortless to use too.

I really like the new menu system, and there are nice little features tucked away in there which I would have loved to have seen on the 5D2 (like the Auto-ISO function is fully programmable so you can specify a range of ISO's and shutter speeds to use, etc).

The sensor does seem to have about a 2-stop improvement in noise-levels. With the 5D2 I would shoot up to 3200iso without having to concern myself with noise. It seems 12800iso gives similar results with this camera. I say similar because the noise does seem to have a slightly different (and nicer) character to it, but there is slightly more of it, so it's not an apples-to-apples comparison. But looking at some 12800iso samples I can see heaps of detail in there (more than my 5D2 at 3200iso), and the noise that is there isn't nasty and can be cleaned up without turning the image to mush. It seems to handle aggressive noise-reduction much better than the 5D2. That's all fantastic news for me.

Chris, that's great you sold your 1D4. I'll have my 1D3 up for sale in the next day or two, and the 5D2 is next.
Do you want me to use the 5D3 this weekend (along with my 5D2)? I just downloaded the Lightroom 4.1 Release Candidate which supports the 5D3 RAW files, but not sure if you are using it. I'm a little hesitent to use a new body for a paid gig straight away because I don't want to be thinking about the camera while I'm shooting, but the 5D3 does feel very intuitive to use so I can't see myself getting stuck in menus or stuffing up settings. And I'll have my 5D2 on my other shoulder (and 7D in the bag) in case.