Hey Michael, to echo what @MCGolfTM said, it is all about personal preference. If you're into adjustable drivers, M5 is the way to go. If you're more in the "set it and forget it" school of thought, M4 and M6 is your best bet.
If you haven't seen it already, we have a super helpful blog that compares M5 vs. M6, as well as comparing the new driver models to their predecessors (M3 vs. M5, M4 vs. M6). You can find that here: https://community.taylormadegolf.com/t5/Blog/2019-TAYLORMADE-DRIVER-MODEL-COMPARISON/ba-p/4952
Hope that helps, and good luck with your search! Circle back here with any questions that us community members might be able to help out with in regards to first-hand experience. I used to game the M3 but recently switched to the M6 (also had the benefit of being able to hit them all!). And let us know what you ultimately land on!