Rhino here in my last two duallies, I agree with Pepp on the non skid with Rhino being just a little softer texture that helps it hold on to your ice chest of beer or whatever your hauling. Then there is Line-X I've found is tough and seems to be a more uniform application. Both carry Lifetime warranties, Rhino and Line-X are both great liners and would not have a problem having either in my trucks, I just prefer Rhino because I seem to always have an ice chest in my truck and hate chasing my beer around the truck bed. But if you are going to haul alot of heavy jagged junk iron in your bed Line-X would be my preference, If your hauling typical loads like appliances, furiture, feed, ice chest of beer, welding machine and just about anything but heavy sharp jagged iron I'd pick Rhino.
This is just my experience and I'm sure there are exception out there.