I shot with a 5D classic for a few years. It did not have MFA so front and back focus was a big problem. I gave up using lens resolution targets, because the problem wasn't absolute sharpness, it was poor focus.
I had to learn where each lens focused and compensate by putting my focus point either in front of or behind the actual target. Of course if your lens shifts as you change focal length, aperture or distance, it gets more difficult.
After much experimentation, I ended up with a target like the one you see in the link below, although mine is a cheaper cardboard version. You just throw it on the floor, put your camera on a tripod and aim your lens downward at about 30 degrees from horizontal. I put a short length of black friction tape across the center of the sheet to create a solid target for the autofocus to lock onto.http://www.hayneedle.com/sale/sewezboard.cfm?source=tellapart
I like this approach over other focus calibration systems, because I feel it is more like real world shooting. I can vary the distance from one meter to maybe 10 meters. I can take it outside and test in natural daylight or indoors to check for low light focus accuracy. You don't even need to uploadload the images to your computer to see exactly where the lens is focused. Just use the LCD screen and magnify as needed.
I normally do this in my studio using the strobes, so I don't even need to use a tripod if I don't want to. For a quick and dirty focus accuracy test, it works fantastically well. It just takes me 5 minutes to test a lens for autofocus accuracy. You can also easily see the effects of tilted or misplaced lens elements. Grrrr...
I hate it when that happens!
With my lovely 5DIII, all my Canon primes focus right on the money with no MFA. I have a 28, 85, 100 and a 135L. My 50mm prime is the Sigma 1.4 which needs a tiny bit of MFA.
Zoom lenses are another story. I've tested Canon, Sigma and Tamron zooms. Most of them have an annoying amount of focus shift with changes in zoom. The best one I've found is my beat up old Tamron 28-75 that I paid $260 for via Craigslist. I will keep that lens till it dies and probably buy another. I tried a copy of the new Tamron 24-70 OS and it was less accurate than my old Tamron.
I am not compulsive about absolute sharpness or corner-to-corner sharpness, because I mostly photograph people. I spend a lot of time with Photoshop blurring wrinkles and hiding blemishes. Sometimes I wish my lens was softer! LOL