NAD 533 upgrades

Well, while I'm starting to save my pennies (it's gonna take a LOT of pennies) for my ultimate VPI Scout -- Grado Sonata front end, I'm thinking of upgrading my NAD 533. It's basically a Rega Planar 2 with a Goldring Elektra pick-up. I just put a new stylus on, and am thinking of a new mat (Herbie's "Way Excellent II") to replace the felt and/or a KAB record clamp. Is it worth doing these tweaks, or should I just leave well enough alone ?? The NAD sounds just fine now, as there's been a noticeable improvement since replacing the stylus, but I seem to be suffering from the " $ 100 upgrade itch." Let me know what you guys think. Thanks a lot.