Can confirm the new DLC area runs about twice as fast as The Island for me. I think it's due to lack of shrubbery, and dark interior environment. It's physically less intensive, doubt it's more optimized.
I'm not buying. WC will never get any more money from me. They broke the game for me and a bunch of people with patch 265, and support is non-existent. Then there's the persistent bugs.... Even if someday they fix it (those of us with this problem haven't been able to play on any server since mid-October), I won't give them any more money.