I've only played a few innings so far but coming from '14 on the PS3 to '15 on the PS4 . . . wow.
Lighting, graphics, crowds, stadiums, just gorgeous.
Defense feels . . . tighter, for lack of a better word. Definitely an improvement, looking forward to actually playing defense more than ever before. Also appreciate the change to CPU defense as well, had a long fly ball last night that went for a double thanks to the CPU OF's route.
New pitch breaks are great, a very welcome addition.
I had to buy '14 on PS4 to carry over my franchise save, but that's all seemed to work very smoothly so far. There are a fair number of guys missing from the game, hopefully that's something that gets cleared up.
I do have to send a very hearty "darn you to heck!" to all the people who have been clamoring for years for that split second delay after the batter makes contact. It's kind of driving me nuts right now.
Directional hitting is a great addition. Might be a while before I feel the full effect of it, but I love that we have that option now.