I feel like this is where I should point out, though, that at 467 meters the single crystal is actually smaller than the one on the Enterprise; if you scale the ship to 622 meters the deflection crystal and deflector dish match the Enterprise.
So, if anything maybe I should flip my explanation and say it was underpowered.
You are saying the one big crystal from the NX version is actually smaller than the one on the Enterprise? That is a surprise.
Weird question, but do you think that it and the deflector dish are a bit "greener" than the Enterprise's? I have felt that way from some shots and images. It might relate to what the function of the crystal is, if it does anything more than just "deflect"-an odd use of the word, but Probert used it that way--the energy from the intermix shaft to other parts of the ship.