Take it for what it is worth - I know very little about you and some of these things may not apply to your profile. You may be a very energetic/motivated and focused person or you may be a person who takes forever to make a decision (the answers would be different for those 2 personalities
).... and there is no shame in taking forever to make a decision - I am thinking of the time I was shopping for pants or shoes (luckily that happens only once every few years)
I have encountered a number of JD/MBA folks and most of the time they did not work in a legal role. They were in real estate, consulting, or making deals for others and I think they were getting an MBA first and JD second. You are in a slightly different boat though. JD first and MBA second. I guess it would not hurt but what is the better option - a stellar lawyer or a middle of the road legal/business guy?
P.S. Business school is very different from the law school in the fact that the future performance is driven by your experience before the shcool.
As someone said it here, bschool is like a car - it can be a Bentley (HBS) or a Volkswagen (Kellog) but at the end, it comes down to how good of a driver you are. A Bentley will not make you drive better. It is simply a tool/machine.
There is a similarity too between JD and MBA - better schools get better job offers and though you are not guaranteed a job, 80%+ students at the top 10 bschools have at least one great job offer at the time of graduation. However, it is less critical than at the law school and you are not ranked at graduation - nobody knows if you were the best or worst student in BSchool. I don't think anyone asks for GPA or anything like that.