I discovered something interesting a while back when the SuperGlide chainrings came out; they're pre-worn-out!!! Well, if you look closely at the teeth profiles, at two spots on the ring, the teeth are half-height. This is to allow the chain an easier time sliding sideways onto the big-ring.

Even before the SG chainring, I noticed that replacing worn-out chainrings with new ones often resulted in poor shifting. After I looked at the SG chainrings, I copied the "worn-out" teeth profiles on a new non-SG chainring. Did this by filing down those teeth to about half-height to match the Shimano ones. Shifting improved significantly!