I think most everything was slightly easier, especially bio and Gchem. I think the real difference is that the actual DAT questions are slightly more basic than the kaplan and TopScore ones, for example, Kaplan and Topscore had these questions where they gave you a diagram of some large molecule, with a bunch of rings, and you had to answer how many isomers this could possibly have. So to answer this, you'd need to figure out how many chiral carbons there were, etc etc, and that was always the hardest part for me, just figuring out the correct number of chiral carbons - so I was worried that I'd get one of these on the actual test.
The question I got on the actual test simply stated something like:
"A molecule has 4 chiral centers, how many isomers can it have?"
While it covers the same topics as the Kaplan and TopScore question, it's somewhat more simple. Though don't expect every question to be that easy.
The one thing that Kaplan did not prepare me for at ALL was PAT. On Kaplan PAT I thought I was doing amazing, especially in angle ranking, I hardly ever got one wrong, but the actual PAT kicked my ass. Angle ranking went from being the easiest section for me to being one of the hardest parts of the PAT. A few of them I simply thought they were all the same angle. I'd suggest doing CrackPAT, I hear that's the best prep there is for the PAT.
I thought RC was just about the same, on the Kaplan ones don't they actually give you 5 minutes less to better prepare you?
QR I thought was a little more difficult with Kaplan than the actual DAT.
Well, good luck, and I hope that helps!