Let me preface this by saying that I own a tutoring company in the Bay Area called Unleashed Learning. We've just developed our own guide for the SSAT/ISEE based in part on what's missing in others. Princeton Review's guide is great for practice tests. They offer a sample one for every level of the ISEE and SSAT, something sorely missing in most other guides. But compared to Arco, their vocab techniques, and treatment of the entire verbal section in general, just doesn't measure up. They do present their math topics very well, but overall coverage of math is a bit too sparse. I've said it before and I'll say it again, for the big name brands, go with Arco :)