Depends on company but the changes really aren't all that you might hope.
Berkeley Review regardless of what they might want to admit didn't really change their books that much it looks like. Lots of re-formatting of the bio section and some new stuff but all in all not that much different. BRTech himself even admitted the physics book hasn't changed much(although I'm not sure it really has to) and I'm rather skeptical the CARs will when it gets released.
TPR: The hyperlearning books haven't changed much. The Bio/Biochem Review book is mostly a bio review book; not exactly adapted to the new test. Idk about the rest of their stuff but honestly outside of those and the psych/soc book there isn't too much else that's really even worth that much consideration(I'd avoid the TPR FL's)
EK: They did make some changes but it's mostly in their passages and FL's(which are very good); the content stayed largely the same and biochem wasn't touched much.
Kaplan: The only material I'd bother with from here is their biochem review. They really don't simulate or prepare for the style of questions the MCAT tests very well; their prep is pretty much content review by and large.
All in all if you want to buy new stuff stick with
1) FL's from EK and Next Step
2) Any AAMC material
3) The Kaplan Biochem Book
4) Psych/Soc review. Best bet is to use multiple sources; EK+TPR+KA is probably your best bet but the thing is you'll probably still end up seeing words on the real deal you never studied for that's just the nature of the beast for Psych/Soc.
5) I would invest in BR FL's as well.