Canon gurus help please!

Canon Gurus I need your help. I'm thinking about upgrading from my 40d. Let me first start by saying I have loved my 40d experience with only a couple exceptions. The biggest of which is it seems to be really noisy at 1600 iso and totally unusable at 3200 iso.

With the introduction of the 1d MarkIV I figured it would be a good time to upgrade to a lightly used 1d MarkIII. This weekend I rented this body to compare it to my 40d. I've really liked a lot of things so far, but in the noise department the 1d MarkIII seems to be only slightly (and I mean slightly) better than the 40d.

So I guess that leads me ultimately to my question. Since I will not be dropping the coin on a new 1d MarkIV, how is the noise on the 5d MarkII or the 7d in comparison to my 40d?

everyone's opinion welcome and appreciated!

I currently have the 40D and the 5D Mark II. I've found the noise on the 5D Mark II isn't bad at all. I've shot anywhere from 4000, 5000, and 6400 ISO. I mean, you'll def. show some noise on darker clothing, and darker areas, but I've been very impressed so far. Others might have more to add or may not be as happy.

I try and keep the ISO as low as I can in each situation, but I'm completely confident when it comes to a higher ISO with this body.

There have been a lot of comparisons done lately. I'd say the 5D2 is equal to the MKIV up to 6400. At 12800 you start to see a little banding in the 5D2's noise where the MKIV's is a little less blotchy. 7D is about a stop behind and I'd say about equal to the 1D3 at 3200 and 6400.

These are from the MKIV. The bird shot at ISO10000 was a bit underexposed and had a bit more chroma noise then it should have. The mantle shot is at ISO12800

Thanks for the input Brad and Rich. I'm still not sure what direction I will go. The more I review my shots this weekend the better the 1dIII looks. I loved the way it felt in the hands and shot. The menus are so similar to th 40d I had it wired within minutes.

After reading a ton of 5dII and 7d reviews, I'm now interested in video. The 1dIV sounds like the camera for me, but I can't figure how to justify the 5K when the wife already thinks I'm F-ing nuts for thinking about dropping 2K on a used 1dIII.

I was told when it comes to video Canon can only record about 12 mins at a time. This is due to the fact that Canon uses CF cards and it can't create a file larger than 4GB.
Is this correct?

The file size is limited to 4 gig or to 29 minutes 59 seconds, whichever comes first. A full res HD clip at 4 gigs is usually about 12 minutes long.

If you don't care about video the MKIII is a great camera.

Rich,
With regards to file size, is that with all cameras that use a CF card or only with Canon?
Are there file size restrictions with cameras that use SD cards?

That is a Canon thing specifically on their DSLR's. On the 5D2, 7D, it's to the CF card cause that's all they use and to the MKIV either CF or SD.