Yes in fact PRITT does not have thermal capabilities but also original ASUS RT-N16 heat-sink doesn't have either, is just PURE glue between both (cpu and heat-sink, ASUS made it that way it's because it's enough to do the job) and so many other devices just like notebooks, motherboards and others have only a kind of glue gum attached (without thermal capabilitie), so i think in some cases you don't need a EXTREME thermal capabilitie because it's not needed, but offcourse if you have even better.
PS: Have you noticed that all thermal sticks have glue on both sides of the thermal metal conductor?
Artic Silver should work fine (or 1 dollar 40mm thermal sticks), but you need to be careful because its conductivity and there's also other "problem" some people reported that you will never again take off the heat-sink, it will be stucked (artic = super glue).
What i will do is to measure the temperature of CPU with the glue and with the thermal stick so i can tell you the diferences, or eventually with my other unit try the artic silver and then compare all the three temperatures, of course it would be better if i could make it with 533Mhz, but i will try at 480 first.