17-4 H900 is harder and stronger than titanium, but of course also heavier. Ti is plenty strong enough for this application anyway.
There was at one time an issue with the taper angle on the EA adapter, but I'm sure they've fixed that by now. Haven't seen one through in quite awhile.
Ours are a little lower profile, and the female threads are counterbored to the depth where they'll have full engagement with no unused threads between the taper and male CB muzzle device threads, so a couple fewer revolutions on installation. Minor consideration.
At the end of the day, I think most people probably make the decision based on the small cost difference and/or preference for a hex shape or spanner notches.