Originally Posted by PB+J

The new system, Mavericks, is going to make everything sound like surf music. All guitars will sound like Dick Dale!

Seriously, it seem possible that different system versions might handle sound differently. Possible, but not likely. Easily answered with a null test

When I upgraded to the new LogicX, i was SURE it sounded different. It was obvious! Till I did a null test with Logic 9, and they nulled completely.

Never underestimate the unreliability of the senses