I'm very happy with the Gauge on acoustic guitar. I
like it on my vocals, but I don't love it...I'm considering a tube mic like the MXLv69. (Remember, this is Low End Theory.)
Here's a recording I made in two tracks, one vocal, one acoustic guitar, both with the Gauge:
SoundClick artist: Kaufman's FAWM Songs - February 2009 - page with MP3 music downloads
Please note that I'm a hack at recording...when things sound bad, it's probably more due to my fumbling and knob-twiddling rather than an issue with the mic. But it does give a sense of what the mic picks up and how.