A lot of people who bought the 24-70 mark ii are trying to convince themselves as well as others that they made a good(perhaps "worth it") purchase. Wake up people don't lie. The fact is, this argument whether the mark ii is worth the upgrade from mark 1 is the same thing as the argument of having more pixels. When you only view the image 100% crop then you will notice those things. Other than that, you will barely notice(if you will notice) the better sharpness. For the record, i owned both but end up selling the mark ii after 2 months of extensive use.
That's too bad you had this experience with the new lens. I think that's the first negative comment I've read. Maybe you had one of the somewhat rare good copies of the MkI, and then one of the almost unheard of bad copies of the MkII.
Well damn! You can't help bad luck! Or maybe it was a case of having out-of-reality expectations. It's happened to plenty of us at some stage with a significant purchase or life decision.
-PW