I do OK with my 7D but you can't beat FF. I would not compare my 7D to my 5D3
I have never really been able to achieve what you want either but this has not prevented me from creating tack sharp prints or on line images. There are a lot of factors involved but PP is important as well. Maybe you are looking for this clarity before PP but here are a few PP tips. Every sensor has an AA filter which corrects Moire patterns and all are different strengths. There are 3 phases of sharpening - capture, creative and output.
Capture you sharpen to compensate for the AA filter when you open the RAW file. Creative is selective sharpening. Eyes only, lips. Stuff like that. Output is for media type - paper or screen? Output sharpening is very important as well. http://www.cambridgeincolour.com/tutorials/image-sharpening.htm
Resizing and sharpening methods are pretty important too. They both work together.Photoshop Top 40 #3 - Image Sizehttp://www.youtube.com/watch?v=PmLDw124uUA&feature=player_embedded#
This is by far my most favourite sharpening method. It is edge sharpening and I sharpen to 300 because you can feather back at the end. No two images are alike. http://www.earthboundlight.com/phototips/photoshop-really-smart-sharpening.html?search=edge+mask&bool=and
I wrote a tutorial which has an action that includes resizing you are welcome to. I used resizing and sharpening methods based on the two videos I posted. http://photography-on-the.net/forum/showthread.php?t=1099897&highlight=really+smart+sharpening
Finally use the masking when you open a raw file. Hold the Option Key (not sure about PC) as you slide to see results. Also edge sharpening. Only the white areas are sharpened so background noise is not. I'm usually at about at 80.