Kaiser you bring up great points. Only way I can tell is over time. I will say that I have 2 Blades strung the same at the same tension. One is stock and one is 355 grams, Sw of 343. Basically a very nice weighting that is not overkill.
I think the only way to find ideal weighting is to start with a lighter stick with a decent SW and play with it for a while until it just gets to where you know the racquet and have an established string setup and tension.
there are a ton of advantages to heavy sticks, but if I am late or fatigued, they are not available to me.
Also, I have to factor in the hot summers here.
One thing I do notice is that with lighter sticks, I have to swing harder. It drains me of energy faster. With the heavier stick I can swing more relaxed and still hit a deep ball. The challenge is to maintain good head speed to keep the ball in the lines.
We shall see how it goes.