That didn't take long...
First one is: Enduro Zer0:
http://enduroforkseals.com/id408.html
Second one is BBinfinite:
http://www.bbinfinite.com/products/sram-10-11spd-road-ceramitech-pulley-set-set-of-2
I didn't even bother to video the stock SRAM ones since the do not spin even one complete revolution. It's hard to tell in the video but the Eduro gets about 8-10 revolutions. The Zero is the baby brother of the Enduro X-15; the Zero cheaper just not as durable but comparable performance. According to my contact the big brother XD-15 pulley's are like the bottom bracket that shares its name. Bullet proof performance for mega mileage and rough treatment. But for testing the Zer0 is a $86 cheaper. The price scale low to high is: Zero, BBinfinite, XD-15. Given the video evidence the BBinfinite would appear superior but given the track record of the XD-15 Bottom Bracket I felt compelled to bring in both brands for testing.
While the video is shocking in the difference; I do actually expect similar performance under load; the Zero were installed Monday and ridden for the first time Tuesday. Once loaded with chain resistance the difference over the stock part was obvious. I had two identical bikes side by side and could tell right away moving between the two rigs and back spining the pedal. I need to do a blind test with Pluckyblond to see if she can which one is which she usually can never tell the difference but, if she can we get a quick answer. After that I'll video some spins to see if it is visually obvious. Then we will install the BBinfinite ones on the bike that still has stock parts and repeat some spin tests. Videos if definitive will follow.
Now as to the why? These things have reported performance gains of 6-15 seconds per hour depending on which source you read. That means pretty much nothing for most of us......... unless you have a 4 person RAAM team riding cross country non-stop for +5 days; that is about 13-30 minutes of free time. Then again there is the psyche out your riding buddies factor if you show them before the ride.
The footnote from the first test ride on the trainer was: Either I had a superior rested day; or I fueled perfectly; or I suddenly made a big performance adaptation because that was the easiest 210 watt 6 x 8 minute intervals I have done all year. Sadly there were about 8 variables in play that day and the pulleys seemed the least likely to have caused that gain but it would be nice to dream it was that easy.