For me personally, the 6x is the better choice because the readability is better during activities due to the larger display. The Fenix is thick on both models anyway. If you have a very thin wrist, the size should not be underestimated.
Hello M Brun. I also decided on the 6 at first. When I had the watch on my wrist, it seemed a bit too small for my purpose and I exchanged it for a 6X. My recommendation.... definitely buy the 6 X.