Justubes2, I am happy to provide more details regarding the Duelund CAST vs. PathAudio resistors. First let me provide some context. All of my testing has been with my DIY speakers (described on my system page) in the high-pass portion of a 1200 Hz crossover which has 4 resistors. I have tried five types of resistors: Mills 12w black body (the old Mills), Mills 12w brown body (new style), regular Duelund (brown body), Duelund CAST (black body), and PathAudio. By the way, some of my comments below relate to bass and one might question how anything in the high-pass crossover could affect the bass. All I can say is it does!
Tonal balance. The CAST resistors are slightly bright and more than slightly lean. To my ears, they are lacking in weight and foundation which gives them overall a "lightweight" sound. I think the mids may be slightly forward as well. In contrast, the PathAudio resistors are pretty much neutral as far as I'm concerned. They may be slightly dark and slightly warm. They certainly had these colorations in the first few days and even weeks, but they gradually disappeared. There may still be some trace of these colorations but if so it is quite minor.
Detail. Both the CAST and the PathAudio have excellent inner detail. I wouldn't choose one over the other in this respect.
Dynamics. Both have excellent dynamics although here I would give the nod to the PathAudio since the CAST is a bit restrained in the bass due to its lightweight tonal balance.
Transient speed. The PathAudio is faster on leading edges than the CAST which has a slight softening on sudden transients.
Overall, I would describe the CAST as having great detail and dynamics but a rather lightweight sound and wispy highs. By "wispy" I mean that the treble is airy and atmospheric, a "big" sound, but the treble is hard to pin down. It is as if the sound is in a fog floating around. I don't know if that description helps much, but it's something that I have heard consistently with the CAST resistors from day one. In contrast, the PathAudio has a solid, direct, clear sound, excellent detail and dynamics, a neutral total balance, and a neutral soundstage perspective. I have no doubt the PathAudio has faults since nothing is perfect, but I haven't identified any failings in my tests.
It might also help to provide some comments on the Mills 12w blackbody resistors, which I used routinely prior to the Duelunds. The Mills are not as detailed and not as dynamic as either the CAST or PathAudio, and they have a lean midbass and slightly crisp high frequencies with a slight edge. However, the Mills do have a solid, direct, clear sound, with none of the wispy quality of the CAST resistors. In some ways, the PathAudio has the positive qualities of the Mills resistors but with a more neutral total balance, more detail, more dynamics and no edge. (The newer Mills brown body resistors do not sound as good in my opinion.)
Of course, the above comments are simply my opinions based on my speakers and my listening priorities. There is nothing absolute here.