I took the MCAT this past April, and the DAT this past October. As far as difficulty, if you have studied for the MCAT, you should be pretty prepared for the DAT.
Bio is easier; however, it is more like intro Bio exams than the MCAT, which has bio-related passages and then some questions that pertain to random bio knowledge. The DAT is all random bio knowledge from all spectrums - my intro Bio did not cover all the parts of that were tested on the DAT so I had to review.
Reading Comp is easier; it's mostly search and destroy mthd. There's a couple inference questions, but not too much
As for advice on PAT - i thought the topscore pacer worked well b/c it let me see which question i should be on. then it was just getting used to the speed.
- keyhole - i had a lot of trouble getting used to the keyholes until i realized that it usually was not as tricky as i made it out to be. conc. on curves and whether a corner is pointed or has a plateau at top and then just rotate it.
- topleftright - just practice and start to recognize that a curved or slant cutout can look just like a rect. most impt. just know how to rotate the obj from top to st8 to left. str8 to side view is you just take the right side (they give you options sometimes where it is the left side to trick you i guess)
- cube counting - i used the baron's mthd. write down # sides of cubes level by level, moving left to right, keeping track, then go back and answer.
I would recommend the Topscore CD and a skim thru of Baron's. Topscore is good in terms of practice and pacing.
Just get familiar with the DAT sections, and then take a practice. Evaluate where you are and where you want to be, and then go from there.
Good luck - you made the right choice swithcing to dentistry!