Did you come to this conclusion by taking snap shots of the tradeshow booth area and zooming all the way in on the rear LCD jpg preview?
My 24-70 II is every bit as sharp as my 70-200 2.8 II. With that said, the 35L was a major dissapointment for me, and I sold it, but it may just have been a bad copy.
Yes I set the 5D3's up to zoom at 100% of the focus point and images were on large Jpeg so would have had some processing/sharpening applied in camera.
Again it's my opinion of 5 lenses I tried, its not ideal conditions but the 35L handled it just great.
Oh my friend who was with me had the same opinion and was expecting better which just backed me up not purchasing it today, maybe next time!!

