Diesel never chewed at the netting. He had been in the playpen since we brought him home. When he was a baby he wasn't allowed to run all over the house. If I wasn't playing with him, holding him, or taking him out he was in the playpen. So really that was all he knew and he was ok with it. I don't really think that playpens are dangerous. BUT a lot depends on your dog. Some don't mind being in a pen and some go nuts and start chewing.
I know we had a Chi/Yorkie mix and she used the puppypad while she was in the playpen. She also shredded and chewed everything up in it. She destroyed it! That was the most destructive dog I had ever seen. So a lot depends on the dog.. She also ONLY used the pad if it was in the playpen. When she wasn't in the playpen she would pee anywhere she felt like it. She didn't even care that you were watching her like a hawk.
A crate will work just as well. I think it is up to you. Both serve the same purpose. Good Luck.