I couldn't tell you the difference, but I certainly feel the difference.
My pre 2011 Jett (I think it was a 2008) broke last year on a training ride, just before a race. Ran and got a replacement Jett.
As soon as my LBS put it on the bike, I could feel it was different.
Very different. So much so I wrote the company. Didn't really get a satisfactory answer..re-design according to " research.." blah, blah, blah.
So I am (unhappily) uncomfortable on the trainer. Just haven't had the time, nor the inclination to start the process again....it really is labour intensive and time consuming. I kept the broken Jett so I can compare it to any saddles that I haven't already tried that pique my interest.
When I find the right saddle..I'll buy a few.
"You can't get what you want till you know what you want." Joe Jackson
2006 Cannondale Feminine/Ultegra/Jett
2012 Trek Speed Concept 9.5/Ultegra/saddle TBD