I did pickup a few pairs of these last week and have been playing with them some. I cant give a real review at this point but can pass on some comments.
The bullet lights are mounted in a small plastic housing, not metal. They seem fairly durable and weatherproof. The color is very white, about like a 6000 hid, but they also sell a blue version of the light. I have left one light turned on for several days continuously since I got them and it still looks fine and is barely warm.
In a dark room, they put out a surprising amount of light and should work well as accent lights, on the bike exterior or underneath. They are bright enough that I cant look at them close up straight on for more than a glance.
They should work well to improve visibility of the bike, but I wouldnt buy them expecting them to do more than that. I mounted one of these as a light in my RT trunk and it does well, but there are probably cheaper options for that.
I did order one of the "PodMod" modulators to try out with the Bike-Vis bullets and will post some comments when I get a chance to test it.
The eBay seller for the bullets has only a limited supply left, about 20 sets, and will not have any more when those are gone. The only other known sources want $40+ per pair instead of $20+ ! Not sure I would invest in many at the higher price.
I'll post some pictures when I get some of these mounted on my RT.