Originally Posted by R600DuraAce
Is not just weight with the SL model. It uses sealed cartridge bearing and the unit is literally waterproof. Longer battery life as well. I got the SL over the pro since the price difference was only $200+.
It's water proof or it's suppose to be water proof. My SL took on some water during/after a rain ride this last weekend and is basically dead (the hub batteries discharge in a matter of minutes due to a short caused by moisture in the housing). The downside to the SL is the fact that you cannot open it up and let it dry out the way you can with the older model. It's looking like mine is going back to Graber for repairs after only 4 weeks and 1200 miles use.