For grid stoppers, other than carbon comps, I do like rikens and that's about it -- and the only reason is that theoretically they have lower noise specs than carbon comp, and are somewhat more tolerant of a bit of excess soldering heat. I have a small stash of NOS rikens in 120, 150, and 220 ohms that I keep just for grid stoppers, though I'll probably use them all up as I complete my new system.
Just as a general note, you can go wild with expensive resistors and easily overdo it and end up with something very harsh or very sluggish sounding in the end. Really best to just try one thing at a time, get used to it/let it break in, add another, do the same, go back and replace the first part, listen again, decide if the first, second alone of the combination is best, make the change, then go on to the next. As you'll see, it can quickly become very time consuming and you may or may not hit on something magical and you'll probably hit on something that just makes your ears bleed :-). Of course, as we've been discussing here, there are just some places where certain types should and should not be considered at all.
I've actually gotten more sonic mileage out of having carefully matched pieces in the same positions on both channels. One reason why I like the .1% vishay CMF-55s -- no need to hand match them or buy large quantities.
HTH,
Jim
