They really have pushed the boat out this time - I'd love to have been a fly-on-wall of the project meeting that first discussed the EX's upgrades and what their reasoning for the various improvements were! You can't beat real metal on a retro bike - one of the reasons I had a Kawasaki W800 but it had to go in the name of the EX...
Concerning plastic vs. metal, I was surprised to find all of the models have black plastic chain guards. The 2013 especially needs a metal chrome one having no exhaust on that side. I bought 2 chrome guards from Mr. T (one for a friend) and have one ready for my DLX when I buy it later this year. The plastic guards look cheap and the chrome adds a bit of class IMHO. I hope the DLX uses the same one as the 2013.
I have fully metal casing guard on my CD90 and the chain is still new and there is no oil anywhere to be seen, lovely.