I myself have been using the NS-2 for the longest of times. I play metal and noise IS a problem, even with the hallowed GT-2.
I've read such topics many times over in various forums. And seriously, how much of a tone nut are we when we say "oh, the NS-2 sucks your tone, less sustain too". Can you really appreciate the difference? I have taken time to fiddle with the pedal and i can seriously say, unless you set all parameters close to max, there isn't appreciable tone loss. Maybe i'm just NOT UP THERE with ppl who can comment about 'tone-losses' or maybe i'm just a simple, easily tone-satisfied player.
I feel strongly for this thread because it's really quite ridiculous, at least to me, when ppl comment about tone-losses due to a noise gate or a similar pedal. How extraordinary is this loss? How appreciable is this loss of (beware of BIG word) FIDELITY or (even bigger word) NUANCE...?
Well maybe, like i mentioned, i'm just not THAT good a player. No intent in this reply, just my thoughts. Especially for those considering getting a noise gate. My advice: just go for it, millions of ppl use it and they can't be all wrong.