I just used this for the first time on a trip to Colorado. It performed very well and received many good comments from others. I noticed the bikes are offset just a bit so they don't interfere with each other. My friend had a diff rack and when using it we had to drop the seats. Not a big deal but shows Kuat attn to detail. The Sherpa is great for your typical MTB's, the NV seems overkill and more suited for DH bikes.
These are fantastic hydropacks. I got one ea for my kids and was so in awe of them I ordered one for myself. I actually got the Raptor 14 which is about the same size but larger storage pockets. As with any bladder you'll need to devise your own method of holding the bladder open while drying. They're like mini backpacks with all the adjustments, which really help with proper fit and keeping things from jingling around while MTBing.