The manufacturers may market them as looking like wood shingles or slate, but in reality they don't even come close. Yet the shingles have some appeal on their own merits. They have greater depth, variety, texture, and shadow than conventional three-tab shingles. That said, I wish I could afford wood shingles or a standing-seam metal roof. Drywall has evolved from being a poor imitation of plaster to a different tactile experience in its own right.
Good drywall is perfectly planar and smooth.
That smoothness can appeal to the perfectionist in us. Plaster is a different experience. It's modulated and textured and acoustically very different. Personally I like plaster better, but I also get a little rush when I step back and look at absolutely flat and perfect drywall. I think blueboard with plaster skim is the worst of both worlds.