My experience...
Chem/Phys: This has been and will always be my weakest section. I can do science, I can do math, but please don't combine the two. Keeping that in mind, this section was by far the most difficult for me. I made the mistake of lingering too long in the beginning and then having the section end right as I landed on my last discrete that would have been an easy point for me.
I think I ended up with 1-2 unfinished, which was really upsetting, but it is what it is. There was more physics than I expected. Less than on the old exam, but you will be doing a serious disservice to your score if you blow off studying physics just because there's less on this test. And just about all calculations I had to do (less than 5 IIRC) relied on one having memorized the equations. They're equations you would expect to memorize anyway, but my point is: study your goddamn physics!!! And of course there was a ****-ton of biochemistry. You need to know how enzymes work and you ABSOLUTELY need to know your amino acids (and, ahem, their codes). Very little orgo, but just enough that again, you really can't blow it off.
Comparison to practice material: harder than the AAMC stuff, but I'm naturally bad at physics and chemistry anyway so take that with a grain of salt. On the other hand, it was thankfully way easier than EK's Chem/Phys!
CARS: I usually dominate CARS and I don't think today was any different. There was one passage that was harder than anything I've ever seen from AAMC, but other than that I flew through it.
Comparison to practice material: Other than the EK FLs, the only other passages I used for this section were from AAMC. I really think the question packs are invaluable. Other companies are good for the practice, but only AAMC's passages are like the real thing.
Bio/Biochem: And here we see biochem once again taking center stage. The new MCAT has a love affair with amino acids; I almost laughed in the middle of the exam. You want to know what makes **** happen in your body. The how is not as important as the what, if ya know what I mean. This section also involved a greater amount of data interpretation than the Chem/Phys section, but there were also instances where I felt like reading the passage was a waste of time. Oh, and study yo lab methods!
Comparison to practice material: very similar to AAMC stuff and a little easier than EK. TBR's passages were good for this section, whereas they weren't quite as helpful for the Chem/Phys (but still worth doing).
Psych/Socio: I maybe spent 5 days studying for this section, to be honest. There were a few terms that were unfamiliar to me, but in most cases could be chosen or eliminated through process of elimination. You absolutely need to prepare for this section through practice passages because simply knowing definitions is not going to get you a good score. I thought TPR's passages were good, maybe a little better than EK's for this. Until we get a good idea of how this section works, you just have to be prepared to encounter terms you've never seen before. Like CARS, this is a section where process of elimination skills are really important. But it's my favorite section!
Comparison to practice material: perhaps a little more difficult than what AAMC has provided, and on par with EK.
Overall: I was most surprised at the breadth of content this exam covered. Almost every topic was addressed in some way. More often than not, any difficulties I had with a question stemmed from my own lack of preparation vs. not having seen the material before. This test isn't a monster, you just need to know your stuff.
I'm definitely Turning TF up this MDW!!! 
