Teflon wire and Tantalum resistors...

Tantalum Nitride, is one of the most stable resistive materials available, until recently very few companies made resistor with this material. Its being used more often now in SMD resistor by companies like Vankel, IRC, etc.
As to why it might sound better???

The only polymer Dialectric I know of thats better than Teflon (PTFE) is Rexolite, a polystyrene with a more orderd internal stucture.

I think Rexolite is an Isotactic Polystyrene, where as normal Polystyrene is Atactic.

Rexolites dialectic constant is flat to about 10GHz, no really relevant in Audio.

Teflons other advantage is how easy Teflon insulated wire is to solder; no melt, bubble, fizz, smoke.

I don't have any experience with the resistors, but have experimented with teflon insulated wire. I stated building my own interconnects and speaker cable about 10 years ago, after spending a lot of money on wires and then wondering if I could do something better. Teflon insulation and solid core wire was my basic component. Luckily, I had a small factory nearby that has been applying teflon insulation for over 30 years and I could go over and purchase a small spool(100'). The other characteristics make it attractive: excellent dielectric characteristics, high melting point.
Originally posted by AudioFreak
Whats so good about these devices that they command such a high price?

Sonics. That simple.
I go with teflon-insulated solid core wire (Allen Wright style) and oce I have settled on a design and do not intend to change values,
I replace resistors by tantalum resistors if I get the values.
Expensive but worth it.

One thing, tantalums are non-magnetic and the internal lead-to-element contacting is extremely good.