I got my Sayoc in the black KG finish with black micarta, I like the look. I didn't plan on using it for breaching or chopping wood, I wanted it dark.
But, on my Camp Axe order I went with the Caswell. I'm going to use it so the finish will be wearing off. I thought maybe a patina would blend in better, or it could be touched up pretty easy if need be. I live in Kentucky, tools rust and all my wood choppers end up getting tree resin, blemishes, and scars. I'll keep it clean and in good shape but it's gonna show some use and wear, and I like that in a tool.
I like the micarta, but I haven't held or used Dan's recycled rubber handles either. I'd think the micarta would be the longest lasting material, it will be there in 100+ years. The rubber "could" dry out, and the wood could do a number of things. It can swell, shrink, crack, rot, get gouged up from use, and although the best looking, it's the more fragile of the three. The micarta will be there even if you use it hard, it could break, but that would be due to some serious hard use.
If you're not in the military, and don't plan on doing missions in the jungles or the Everglades, would you want the rubber handles? Are you a Navy SEAL, will you be swimming with this in ocean water before a landing?
I imagine that rubber grips are great for very extreme uses, maybe a bit overkill for the civilian, IDK. Dan's video, on the WK2 website, demonstrates how tough those rubber handles are, they are on that small rescue/breaching axe with the can opener.