My opinion is that there was no more math beyond multiplication and division, simple log manipulation and dimensional analysis. There may have been a few more questions that required math, but not many more. I think the perception of heavy calculation may come from the fact that you're taking the real thing. While you may be comfortable estimating and rounding in your head for a practice exam, people tend to think: "This is the real deal. I need to get this right." and do less estimating. Consequently, they spend more time on calculation-type questions.
I think it would be a mistake to spend additional time learning or reviewing math at the expense of understanding relationships in equations. Maybe drill a little bit so computing moles/liter from grams/mL is not time consuming or something, but beyond that I question the return on investment. It would be misleading to portray the MCAT as something other than primarily concept-oriented.