the noise won't be pronounced if the guitar's signal lies above the noise... and if you really have that much noise, you are going to want to look at your cabling, sheilding, pickups, effects, tubes and the wiring of your playing/recording area. a good compressor doesnt really mute anything, and it's purpose is not noise reduction. it seems like you're saying that a noise reduction unit, a completely different tool with a completely different purpose, will replace a compressor. noise reduction sometimes involves frequency specific compression and gating, but in no way is it going to function as a broadband compressor, catering to the whole signal.
the rocktron doesnt create any clarity, it just removes the dirt from your signal, and i think the causes should be looked at first. i'm not saying the thing isn't useful, but as a tool for getting rid of unwanted noise, it seems skewed to have that as the main tool in your audio arsenal.