I have the E302 model on my R90/6.
Only had them about a week but I'm happy with them so far.
They're replacing some Hagons and I like them better.
Could be that it's the fact that they're "set up" for my weight and the Hagons were bought used from someone 20 lbs heavier and he had him made for his weight.
I was trying to sort through the YSS information and it seems that the 302 models are all the same core and that each step up (and increase in price) adds a feature or two.
E302s have only preload adjustment.
More $ = rebound dampening adjustment.
More $$ still = adjustable compression dampening and ride height adjustment.
Mine came right from EPM Performance Imports (Klaus Huenecke) and they shipped within a week of them having all my information.