Yes, the earpads and headband are top quality leather.
I suspect the Signature PRO was purposefully kept as utilitarian in design as possible, and that Ultrasone is directly responding to the criticism they've faced from their Edition series. That is, people are quick to target the Editions as being about luxury image and little else. Ultrasone is oft cited as being all sparkle and no substance.
The Signature PRO isn't a cheap feeling headphone. Holding it in your hands, you can feel that it has some heft and that it's built rock-solid. Even though it lacks the metal of the Editions, it feels stronger, and it's actually a headphone I wouldn't worry about taking out and about. It's not a headphone you have to baby, and personally I really like that.
It's not like Ultrasone doesn't make a distinctive looking, nice sounding headphone already. It's called the Edition 8. The Signature PRO has a somewhat different sound, but sounds just as good---if not better---and addresses different needs.