I'll be submitting a review on the GR-1 by Vibesware, but wanted to give it a two-thumbs up and provide some of the highlights to this unit (check out the site at Vibesware.com for video demos). Anyone else try this technology?

• There is nothing to hold, you don’t have to buy special guitars, and you don’t have to modify any guitar;
• It allows infinite sustain with or without feedback (an addictive element for rock guitarists);
• The effect is reproducible, quick (faster than what can be produced with a cranked amp) and responsive to the player;
• Different harmonics are possible depending on where the unit is aimed at the neck and whether you chose to shift the GR-1’s head along the neck;
• Any pickup selection works and each produces slightly different harmonic capabilities (as does humbucker vs. single coil);
• Feedback is achieved even at the lowest amp levels, through headphones, through a PA system, etc.;
• Up to three strings can be stimulated to produce sustain/feedback and the player can determine which string dominates the harmonic spectrum;
• You can alter the intensity of the effect through body position and/or volume output of the unit;
• The nuances of the sustain and feedback takes on the characteristics of the guitar player’s personality;
• It works with clean or dirty amps and does not alter the original tone(s) of your gear;
• The nuances vary relative to the gear, e.g., use of a Whammy pedal, Wah pedal, etc.; and
• It is very natural sounding, like an actual amp giving feedback, as compared to other sonic string stimulators.