Yep, all of the above... back when it was "dope and cotton", it made sense to plaster metal on an airplane. Now, the fabric lasts alot longer, and protects so much better, that it's the best way to go. If you think a metal airplane is better to have tied outside...just look at two sitting side by side, one with metal and one with good fabric, after some hail... I'll take the fabric.....

(yes, after SOME hail, it's not going to matter much..but up to a certain size hail, the fabric will give and come back, where the metal wont) I converted a friend's Stinson back to fabric years ago, and it wasn't all that bad to do. All the formers and stringers were there. He said the performance jump was unbelievable! He'd been flying this plane for a couple years, and was happy with it before, but after the metal was pulled and it was recovered, it was a much nicer plane that performed better, according to him. The weight wasn't as much as I thought it would be (something like 30# heavier with metal if I remember right?..it's been alot of fabric and years since I did that one) but he swears it's quieter and flies better!
JH