There IS one reason to choose one over the other, and its not quality, or even the design features.
Commonality of parts.
The little things, setscrews, decapping pins, lock rings, seating and decapping stems etc. Things the die makers will fix or replace once you contact them, but can stop your reloading session until that happens.
Having some spare parts on hand, even if cannibalized from other dies of the same make might mean the difference between being able to finish that batch of shells tonight, or having to wait a few days.
If most of your other dies are Lyman get Lyman. If RCBS get RCBS. If you're only loading one caliber, flip a coin.