Pushing Electrons was a recommended book when I took Orgo 1 and 2. I can honestly say that I never used that book.
When I was prepping for the DAT, I was enrolled in summer Orgo 2. The first 1/3 of that class was a review of Orgo 1, so that really helped in my preparation. So on top of all the reading/problem sets I was already doing for my class, I found Kaplan to be an excellent review/aid.
Also, my professor for Orgo 1 was nice enough to email the final exam review which included a multitude of problems and key sections to review, all of which were relevant to the DAT.