Does my 24-70 look sharp to you?

I've had my 24-70 2.8 L for 6 months now. I've never quite been satisfied with the sharpness. Sometimes I can get some nice shots, but often it just seems soft. Now, I readily admit it very well could be me. I am an amature, for sure. Below are some shots I took:

All were taken on a tripod. I did not use mirror lock-up. They were all taken with 50D at 70mm from a distance of about 3 or 4 feet and RAW 100 ISO. Converted from RAW in DPP (with +1 contrast and 3 sharpness) to 16bit TIFF then to max jpeg in PS Elements. No additional processing was done.

Below are resized jpegs and also 100% crops from the focus point. Focus point was the center of the 100% crop.

Below are the 100% crops.

The 2.8 looks especially soft. I know I can't expect as good of results from 2.8 as from, say 7.1, but the 2.8 looks too soft to me and is typical of my wider aperture shots. Is it just me pixel peeping?

Thanks for any thoughts. Even if those thoughts are that I am just nuts.