As someone that teaches both the LSAT and GMAT, I can tell you that the LSAT is way harder to prepare for than the GMAT. The LSAT has the "games" section that is absolutely nuts compared to any other standardized tests I've seen, other than some high-end IQ tests.
As for the use of the JD/MBA, I'm not qualified to say anything about that, so take anything after this for what you're paying for the advice. I have a JD, but not an MBA. Took the GMAT last year, got the 720, 80/80 split.
I started reading a book by George Ross, (Donald Trump's right hand man). He has a JD but not an MBA. He had the best explanation of how lawyers think compared to business people and I think it's a very important observation. As an attorney in real estate deals in a firm, he always analyzed the deals in terms of problems to be avoided. His clients that were working the real estate deals approached the problems from the perspective of "Will this be a deal-breaker?" or "How much will this cost me?" Those are two totally different persepctives. As a lawyer, we think very different than business people. If you want to do business, being a JD will most likely give you some instant credibility with people, but in the end, you still have to produce in any environment be it business or legal.
If you're interested in this book, find it here:
https://www.amazon.com/Trump-Strategies- ... 471718351#It's a fascinating book and a quick read.