I'm pretty sure I already used words to say why I think the reward is only mediocre:
"The reward is having 1 extra forward who's fresh for 20 minutes or so, versus a 6:2"
1 more fresh forward for 20 minutes isn't really what I would call a huge advantage, adding nitro, or anything else like that, it's an extra couple of percentage points. It'll make a difference in a tight game maybe by as much as a single penalty versus not having that 1 extra forward. It also comes with the sacrifice of a fresh back, so even the advantage is swings and roundabouts (a greater gain than loss, sure, but nothing revolutionary.
It's also... an opinion - not everyone has to agree with mine, or yours, or Matt Williams'
I've not seen anyone failing to see the upside - just disagreeing on how much of an advantage is it versus different balances of bench selection.