My opinion only, the use will drive the choice of which dot to get. The gold standard for defensive use dots is the RMR Type 2. The SRO is said to be “not for duty use,” and is Trijicon’s effort to cross over into the competitive world. The Holosun 508 series gets great reviews and appears to be rugged enough for defensive use. For competition, it’s pay your money, take your chance. I have Romeo 1, Romeo 1 Pro, DPP, C-More RTS2. Just get 2 of whatever you choose.
If I were starting from scratch, I’d probably go SRO 5moa. As rugged as you can hope for, big lens. Carry it or compete.