<Don't forget check the focusing accuracy with both MF lens and AF lens.>
You have to be careful with this one. While true, it introduces a variable outside of just the SLR body. If this is part of your testing, the lens has to already have tested to be accurate and you need to have a repeatable methodology.
One of the related ideas is to make sure any focus adjustment in the DSLR is set to zero or neutral. If you buy a D300, D3, or D700, the camera has a focus adjustment that might be used and based on someone else's copy of your lens.