I got this plug when it first showed up on the scene a while back. The frequency response is definitely not flat by any stretch of the imagination. I tried it on drum overheads and even there, I was less than impressed. I couldn't imagine trying to use in on a vocal, unless you were going for that low fi sound. It definitely has character, no doubt. As Nick described, it could have it's uses. With the severe low end cut, I don't think it sounds good with bass guitar. YMMV
As I mentioned before, this plug doesn't do too well with N-track 3.x It works fine with Samplitude. Apparently, it's an N-track issue. What else is new?