EK and kaplan are good depending on your weaknesses.
kaplan has more academic passages which reflect the MCAT much better than EK's passages with really vary from interesting coffee table reading to the academic(perhaps more realstic sampling on the MCAT).
EK's questions are on par with the MCAT while kaplan's questions did not seem to match the feel of MCAT questions.
EK seemed to give solid indication of my MCAT capabilities overall. kaplan did as well but in a more stressful way. You need to be able to digest those FULL one page academic passages and kaplan has a lot of those.
If I had to choose one I'd go with EK. As I said both are good and one may be better for you if you know your weaknesses.