Mine came in last night (
http://www.amazon.com/gp/product/B001SUZNGW). The shipping estimate between May 20 and June 1 was spot on. The box was a little squished on one side, but it's very sturdy and the contents are well packed in foam.
The installation on my Scorpion EXO 900 was very straight forward - there are indentations in the shell that are the perfect fit for the speakers and the mic boom. I used the screw-on mount without peeling off the sticky since it doesn't lean on my helmet when mounted like that. I'll try the stick on too, just to see how it will hold. The double sticky is 3M so it should hold well, but if it doesn't I'll replace it with something industrial strength. I don't like screws, besides I can use screw on mounts for extra helmets.
I just tested the performance briefly and it seems OK, although with a few initial glitches. One unit appears to be charging erratically and for too long (the red light doesn't go off, and then it does). The other looks like it has a flimsy audio connector that looses contact. Will investigate further.
The units pair nicely and connect quickly. I didn't need to read the manual to figure them out.
Volume control is in relatively big steps. It would be nice if it was more gradual, but it's not a deal breaker.
Audio quality seems to be in line with what others experienced - good enough for voice, a bit too tinny (no bass) for music. I plan to address that question later with higher quality headphone speakers, although using several earbuds/earphones (Panasonic, Sony, Blackberry) did not yield a big enough improvement in sound quality. Distortion is quite noticeable at higher volumes with any output device I tried.
That's the preliminary experience, more when I get a chance to try it out in the real, moving, buzzing, vibrating, buffeting, yelling... world