He who is Xeno said on Tue, 14 Nov 2017 15:35:55 +1100:

300 pound extra clamping pressure on the clutch plate. Ergo, reduced
likelihood of slippage under extreme conditions.

There must be a tradeoff, simply because there always is a tradeoff.

I get the 1/3 greater clamping, so, in *extreme* loads, like towing a
trailer up the Sierra Nevada mountain range, the 1200 pound should slip
less.

What happens under normal loads?
Nothing different?