yes mic sounds are always better however, look at it like this from a performing musician stand point...most sound guys use 57's (i mean hey its the industry standard) which they haphazardly throw infront of a randomly chosen speaker, if you have ever mic'd w/a 57 you'll know you can get a great sound when you find the sweet spot, but if you miss that spot (and they often do) then is sounds horrible... the other is a senhiser 609 which i prefer but most sound guys sloppily drape it over the cab and there you go
the sound guy doesnt really care too much about getting you great guitar tone, he cares about getting you on and off stage as quickly as possible, plus if you are in a band like mine that actually PUTS ON A SHOW, then it can be open season on mic stands especially on smaller stages
so all things considered i say the mic eliminator is an excellent tool, you get the sound guy a great tone, he doesnt have to fool with the mic, you know the tone is good, and no worries about bleed through, or a mic getting moved...
the way we're going to be running it is... i bought on (like i said been using it in the studio) my other guitarist built a box for it, I'll be running in one side, he'll be running the other (since it is stereo) and viola' great tones no fuss, just a couple extra cables!