Upgrading...1Ds mk2 or 5D2 ??

Looking to purchase another camera to use mostly in the studio to gain some image quality and am torn between getting a used 1Ds mk2 or a 5D2. I currently have a 5D classic and am very satisfied with the performance of this camera but would like the higher pixel count and IQ of either of the 2 aforementioned cameras. I guess my question is which camera would give me the best IQ for doing BIG prints and render the best color and sharpness overall. I don't want to spend more than 2 large for another camera, so a 1Ds 3 or 4 is out of the question. I definitely like the full frame over the crop body. Having researched quite a bit I have settled on these 2 and would like to hear from people who have had experience with either or both of these cameras. Thanks for any input!

you can't mess with a 1d body. I used a 1ds mkII for a wedding once and didn't touch the 5dmkII I was also given to shoot with...it just *feels* better...but i did feel the IQ was better on the 5dmkII, though,indistinguishab​le from a 5d

I just tested bot side by side for iq, there is a small but noticeable resolution gain with the 5d2, but not enough to make a big difference. To me the colors and depth, sharpness etc were pretty comparable.

That's where the similarities end IMO. The 1d feels and handles so much better, it has two card slots, the AF will be much better, but replay etc are a bit faster on the 5d. For me if you don't need or want the video it's a no brainier, get the 1ds2.

For BIG prints, no contest, 5DII.

What about high ISO? I would expect the 5d2 to have the edge there because it is a more recent sensor.

Depends how important that is to you of course.

Being that most of my shooting is done in the studio the high ISO isn't really much of an issue.....I would really love to be able to shoot as ISO 50 though!!