As long as you are giving yourself enough time to prepare, I would definitely go with the
MGMAT series. It's more thorough and really helps you nail the fundamentals. 200 points is by no means a modest score improvement so you will definitely want the solid grounding
MGMAT provides.
Make sure to also work with official guide material (OG 12, OG Math and Verbal) so that when you are learning the strategies and concepts from the
MGMAT series that you can apply them on actual GMAT questions. Of course
MGMAT writes high-caliber questions (indeed they are often harder than actual GMAT questions) and you will want to use their practice tests.
Good luck!