I bought this pedal to see if I could at least reduce the noise coming from both my amplifier and pedal setup, specially when recording. I'd known Yngwe Malmsteen himself used it live, so what could go wrong?
PROS:
+Reliable (BOSS pedal standard)
+Efficient
+Versatile (send+return loop and three cable method)
+Good looking
+Buffer
CONS: No negatives.
You can sucessfully use it for specific pedals/group of pedals (after them or through the send+return loop), but in my case the noise also involved the amplifer itself and that's where the built-in superpower inside the NS-2 comes in, the "three-cable method":
[Guitar>Send>Output>Return(Amp)>Send(Amp)>Input>Return>Input(Amp)].
With this kind of chaining method, BOSS designed the ultimate noise killer in my opinion. Not only you vanquish the noise of your pedal army, but also the screams of your amplified dungeons of doom. I don't even play metal, but I just had to say that.
Your tone will be preserved (I promise), no sketchy EQ changes at all. If anything because there won't be any noise you'll actually lose some annoying ice-picky high end (swear to god). Just listen patiently to how the decay and threshold affect your sound, put the reverbs, delays and modulation after it (it's in the manual) and rock on!