We just spent three days there last week. My experience:
Downtown Disney:
Traffic in and around is a huge nightmare due to work being done. Take a bus if possible and time your pickup right, or get there really early. Walking through DD, Passing by Paradiso on the way to the market, you can audibly hear circular saws buzzing constantly. Barriers are placed awkwardly cutting off the west side from the market directly (you're forced to cross to rainforest cafe). It is a bit of a maze to get around.
Magic Kingdom:
Of course there's the barriers with the fake printed trees around the castle. There's also some covering up happening on main street.
Epcot:
Didn't notice anything, only did future world.
Animal Kingdom:
Barriers are up between Dinoland and Everest. Only did those two areas.
Hollywood Studios:
I really didn't notice anything other than closures. ToT, RnR, ST, MV3D. Of course there's that dead space near the back lot.
Overall DD seems to be the worst imo right now. It's not that bad, HS is fine if you just do fastpasses