Here are some of the details on what has been tweaked in the Legendary Edition with regards to gameplay.
How we rebalanced, tuned up, and mechanically improved the remaster.
www.ea.com
Honestly most of it looks good. I am eager to use the Mako with the changes they have done. Oh and of course the native 21:9 support.
One thing I am curious about will be if the visuals are going to be better compared to the originals with mods like ALOT. I think I will take a few screenshots for comparison. I still find it almost funny that the game I am looking forward to the most is an old one I have played many times.