Does taking the multi state bar exam give you more options?

The Multistate Bar Exam is administered in most U.S. jurisdictions and territories (i.e., you'll have to take it in almost every state and territory in the nation (excluding Louisiana and Puerto Rico).

All states and DC have different requirements for becoming licensed to practice in that jurisdiction. Most I believe require you to take the multistate exam and receive a certain score on it before you can practice there. Once you become licensed in a jurisdiction some other jurisdictions allow you to waive into that jurisdiction based on your score on the multistate. So yes, taking the multistate may allow you to waive into a jurisdiction without sitting for the bar in that jurisdiction. Some require you to take the bar exam for that jurisdiction and don't allow waive ins so do your research before taking the exam.

If you're trying to differentiate the MBE (Multistate Bar Exam) and the UBE (Uniform Bar Exam), the MBE is a portion of the UBE, which also includes the Multistate Performance Test, and Multistate Essay Exam. I think almost every (if not, every) state in the U.S. requires the MBE as part of their exam requirements. If you sit in a UBE jurisdiction (only a handful sprinkled throughout the country), you would take all three portions. The benefit to taking the UBE is your score is more portable, meaning you could take your score and qualify for admission to any other UBE-accepting jurisdiction (assuming you meet the local requirements: character and fitness, MPRE score, etc.)

You can find more information at the NCBE website. Good luck to you.