Yeah, it's grippy alright. It'll help against the "sweat escape" and its extra grip will help hold a limb in place while working for a sub. As people have said though, it won't replace bad technique, but it will help in those odd situations and prevent sliding out of locks more frequently compared to standard shorts.
That said, some people will notice it more than others, and with new products like this only time will dictate wheter it becomes the standard or just a passing fad. Check out the uber-lengthy Gripflex thread for a few various opinions.
I have to add that these are great shorts even without taking the grip panels into account. The material of the new Sprawls has been improved, and I would've still bought them even if they hadn't had the new grip panel tech. I admit that it was curiosity that made me make the purchase initially, but I would buy another pair of these shorts regardless of the grip panels, which are more like a plus to me to go with the quality of the shorts.