Even as a weekend warrior I would do a liner. Even just a plastic drop-in liner would be better than just a rubber bed mat. I've had the rubber bed mats before and I like them, but only as a supplement to a lined bed and not as a replacement. There was one in my Mazda and the sides and wheel wells looked like hell. Personally, I think all of the truck companies should make the beds out of steel with a composite inside lining right out of the gate, but since that doesn't happen a spray in liner is the next best option.
As for Rhino vs. Line-X: I've used both on my fleet trucks at the office and haven't noticed any long-term difference on durability, and these guys are hard on truck beds. I'm not sure what kind is in my truck - Leonard Truck supply did the spray-in for my dealership on my truck - but I like it. It's durable and I've dragged a lot of rough stuff on top of it. Worst thing about it is that it's really hard on the knees. I am seriously contemplating getting the truck rug as I have a camper top on my bed.
Weight: The spray in liner stuff weighs nothing. It's not going to help you for winter driving. If you don't have a 4WD, you would definitely be helped by having some significant weight over the rear axle in the winter. My old neighbor - a Luudite that couldn't be convinced of the value of buying a 4WD - would spend the entire winter with a cord of wood in the bed of his truck. To his credit, *most* of the time he did make it home (we live in the mountains) but not always. I, on the other hand, always made it home. With a 4WD. But years ago when I was a kid no one had 4WD unless you had an old jeep. Once in a while you'd see a farmer with a 4WD truck but even those guys mostly used 2WDs. We just swapped tires twice a year, kept sand, blankets and a half shovel in the trunk/bed of the truck. You could always do that, or if you live in a snowy place, just bite the bullet and get a 4WD. I've done it both ways and I prefer pushing a switch and staying warm
