Got my new one from Sweetwater today, and I love it!
There's still definitely an artifact if you push it all the way to the end of the cycle, but once you find the sweet spot, you can either leave it on all the time, or use the momentary function to use it selectively.
Is it a Sustainiac or Fernandes Sustainer. Not quite, but it's leaps & bounds more functional than the BOSS FB-2.
I've run it through the paces in just dry crunch like a rhythm guitar setting ala Malcolm & Angus, and I've tried the Ted Nugent & Satriani feedback tricks with it, and I think it's quite useful for this.
Especially considering that I use a POD HD500X & In-Ears, so it's just gonna give me more of that guitar/amp interaction vibe in my context.