My 12 month old girl is teething, and while she's not very destructive, she is mouthing EVERYTHING! She's constantly chewing on this bed (despite all her toys) and this bed has withstood all of it! It's not indestructible so I wouldn't put it in a crate unsupervised if your pup is teething, but it's the strongest bed I've ever seen.
Also, she's crazy about this thing. It's very overstuffed and cozy. When I opened it up, she was already sitting in it before I put the pillows in. She'll even drag her blankie over and then climb in. All her toys end up in here too, so I guess it's good for clean up? She's about 12 pounds right now and 14 inches tall, and I got the medium. It's really big for her, but she loves the space and rolling around in it so I'm glad I went up a size.