I agree. 35L is sharper than Nikon, Sony and Zeiss equivalents.
As I own both 35L and 50L, I can say 50L is very sharp as well.
At f/1.4 both are almost equally sharp with 35L leading.
At f/4 roughly the same.
But they are different focal lengths and 50L is the sharpest DSLR 50mm lens
. Only Leica 50mm f/1.4 Summilux ASPH is slightly sharper at f/1.4 for 3 times of the price.
Leica 50mm: http://slrgear.com/reviews/showproduct.php/product/1503/cat/107/date/1336701679