I did a few more tests and what I found out is this - even when I cropped the 5D II image to match the 7D one the full frame image looked crisper, was 2/3 of a stop brighter, a bit colder in tone and showed less CA. Due to the effect of compression with a tele lens on the 7D the subject looked bigger in relation to background than the cropped version of the 5D II. Naturally. Though due to this its hard to determine if one is resolving more than the other. To my eye I could see tiny cracks and hairs on the books on both images. If anything I have now realized my 135L works better on my 5D II!
It would be helpful if you provided full size files with EXIF. Sorry, but your findings just don't fit the facts, the math, or the theory, otherwise I wouldn't ask. Did you configure AFMA for the same lens on both bodies (it is possible the lens was not calibrated properly for the 7D.) Anyway, images w/ EXIF would be nice, as I know my stuff in this area pretty well.
I really need to just bite the bullet and buy the 5D III. I've been waiting for the 7D II to be released, to see if it would fit my needs better, but I'm tired of renting gear all the time to prove my points...
If it helps any, Roger Clark, a well respected scientists with I believe multiple Ph.Ds, has an excellent page demonstrating how much more resolving power the 7D has in focal-length limited scenarios, and the 5D II is one of the cameras tested and compared:http://www.clarkvision.com/articles/telephoto_reach/index.html
The second image on the page shows the moon shot with the same lens (300mm f/2.8 L) on four different cameras. The differences in resolving power for each sensor are more than clear. The 7D moon is about four times larger than the 5D II moon, and the additional detail is very clear.
Here is another link, where Roger covers noise and high ISO:http://www.clarkvision.com/articles/pixel.size.and.iso/index.html
To quote his assessment:
Here is my assessment:
In all the images, the 5DII images fail to show the subtle color differences that the 7D and 1D4 show. The color in the 1D4 and 7D are very close (until noise hides it).
ISO 100: 7D noise is small and detail is well above other images. 7D=top, 2nd=1D4
ISO 800: 7D noise is showing, but the detail is still well above the other cameras. 7D=top, 2nd=1D4
ISO1600: 7D noise is becoming prominent, but image detail is still very good. 7D=top, 2nd=1D4, but the difference is narrowing.
ISO3200: 7D noise is becoming objectionable and color is getting lost, in particular in Mare Serenatatis (the large circular dark area in the upper center). top=1D4, 2nd 7D. A good down sampling algorithm (like 2x2 pixel average) could improve the the image.
ISO6400: Noise is too apparent in 7D, and 5DII (which is slightly older technology than the 7D or 1D4). Top=1D4, 2nd=5DII. In my numerous sensor evaluations, I consistently see the 1D series sensors have fewer hot/bad pixels and the images here show that too: the 7D and 5DII images have a lot of "spiky" noise not seen in the 1D4 image.
In all the images, if we boost the low level, we will see that all the 7D and 5DII images have a lot of fixed pattern noise, which decreases as ISO increases. The 1D4 has a little fixed pattern noise at low ISO which quickly decreases at intermediate ISOs. The noise is illustrated below.
It is only when he reaches ISO 6400 that the 5D II even really becomes a contender. At ISO 3200 the 1D IV finally edges out the 7D. At all other settings, the 7D has a considerable resolution advantage that definitely shows. These findings jive with my own experiences...the 7D is an excellent camera that far outresolves most other DSLR cameras (with the exception of only a couple new ones from Nikon only recently released (D3200 & D5200)). No matter how you slice it...the 7D trounces the 5D II and the 5D III in terms of spatial resolution. Assuming you are not noise bound, in any focal-length limited situation, the 7D will produce better results.