DK's NEX-5 writeup
"It was rumoured that these lenses would be branded as Zeiss. Having used these two, I can’t say they would ever have deserved that. Both are very sharp centrally but pretty soft at the edges unless well stopped down, and both have fairly strong CA."
In a thread awhile back about edge softness of the CZ 24-70mm f2.8 this characteristic was described by some to be the hallmark of a Zeiss lens and to be valued.