Similar player, but Djokovic does everything just a bit better. Updated forecast I saw does not look like rain will be an issue. I don't see any reason it won't be open based on what the weather says. Wind effects everyone IMO. It's a matter of who gets to serve with the wind in the "right" direction at critical times or responds to it better. I think that's more of an in-match adjustment that you will have to wait and see about.
I'm assuming that Gilbert thought that Djokovic would have an advantage indoors. I am not as miffed by Djokers performance against WaWa as others- Wawrinka plays like a bull & Djokovic seemed to try to just outlast him and hope for mistakes (hence the non-exsistent winners for the most part). Murray does not consistently put the thump in the ball so Djokovic will feel far more comfortable with what he can do versus Murray. Murray is obviously one of the best movers, but so is Djokovic. Murray would have to serve awesome for 3.5 hours for me to feel as confident in him compared to Djoker who has served great all tournament. Djoker finally got his first test last match and I think he will be ready for Murray.