Yes, my has Mac has been scratched by my wristwatch before, so for all my Macs I buy the Moshi Palmguard. Now it's the plastic cover that gets scratched.
The added advantage is I can rest my bare palms on the computer in cold winter months without touching a freezing computer.
I don't, but my girlfriends bracelet sure did and she was only typing in a password, with the computer on a desk, from standing height. So it was a soft touch, but noticeable scratch.
Yes it does. The corner of the palm rest on the left is all silvery since my watches band has scrapped off the coating there. Doesn't bother me very much.
Having scratched my old MBP's palm rest, I've subsequently installed skins. I had a ZAGG invisible shield on my early 2011 model and have an iCarbons one on my current system.
Well, when I'm wearing my metal watch it's constantly catching against MBP's corner. It didn't cause any scratches, but I did
get a palmguard
and I take off my watch when writing
Somehow it happens only on my 13" cMBP. I have no such problems with 15" cMBP or the 13" Air.
Anyway a palmguard is good choice. I think I have one from Moshi - it's very solid and very Macbook-aluminum like