For almost every gun out there you have a choice between speed and accuracy. The load that gives you the best of 1 usually doesn't give the best of both.
Its like cars, you can have fast or you can have longevity. In the car world you're usually tooling around town or down the interstate on 20-30 hp. Even if your engine peaks at 500000hp, you do almost everything on 20hp. I can take a 300hp engine, spend 20k on it to make it a 500hp engine, and it will spend 98% of its life making 20hp. Is up to me to decide if i want to spend the money to make 2% more fun, and if I'm willing to accept the additional wear and tear.
Or i could buy a car with an engine designed to hold up to 500hp and either be happy, or spend 20k to make it a 700hp...
No matter what you end up with, theres always the option of spending more to make more. And you'll still almost always need, 20hp.
The next one up will always have a higher potential.
Its almost purely the ops subjective choice, either will do the same job. 1 can just be pushed a bit more than the other.