If we're comparing AS and AA adhesives, I'm not sure. I don't know if they still use the Arctic Silver I formulation for the AS adhesive. If so, AA is a little bit better than ASI.
I usually make my own adhesive - AS2, 3, or whatever I can find, in the middle of the chip, and a few dabs of regular epoxy around the corners. This provides adequate adhesion, while still giving you at least some chance of removing the heatsink later, without ripping the chip off the board with it.
This lets the thermal compound work best, uninhibited by epoxy.
Does this Zalman heatsink have clips for the motherboard? If so, you don't even need adhesive - just plain old Arctic Silver 5.