I haven't, yet, tbh.
Done a fair bit of review-reading. The general feeling seems to be that other than very, very slightly improving some of the graphics the game remains exactly the same other than Steam multiplayer support and Steam Workshop.
Neither of those things I need - GameRanger serves exactly the same purpose and there are tons of modding communities that have vastly more mods that Steam Workshop (at least for the time being).
The "HD" release offering so little, whilst at the same time dropping Forgotten Empires, is a no-brainer to avoid it for the time being.
I'm also a bit irked by them calling it "HD" - I think this is really quite misleading. The difference in graphics is pretty negligible. The amount of money they've made from this "HD" release (It's actually #1 sales and ahead of Bioshock Infinite on the Steam Store) should have easily allowed for a
much bigger budget - One that might have helped them do more than run a dishcloth over what is arguably the best RTS of all time. Even with a tiny budget, though, I'm amazed the development team has managed to get away with doing so little. (Interestingly - a good few of the top downloads on the
steam workshop are for the
old terrain graphics. People have literally bought the game for Steam multiplayer support and shrugged off the "new" graphics).
TL;DR - Forgotten empires has done far more for the game than this HD release - I'm sticking with that for the time being. If the Steam workshop really takes off and some half decent graphics improvements get implemented I'll pick it up eventually)