If you are not using a Great Maul or similar and wanting crushthrough or knockdown, the stats to me suggest very high PS is not worth it in most cases. Two good hits will kill most characters, unless they're tanks, so the main reason to go total str is a one hit kill...
Even with a monster damage weapon like a +2 Claymore or a basic Great Long Axe (45) against someone with medium armour (say, haubergeon and mail mittens for 42 body armour) you will average 40 points damage with a maximum of 57. You will only one hit kill an agi build and will have to be lucky to do that. A heavier armour character, for example, coats of plates & Wisby gauntlets totalling 55 body, takes an average of 32 and a max of 48 which will almost never kill in one.
It's more complicated than this, of course, because most of our kills (contrary to what we want to believe) are not in fiercely fought duels, they're from opportunistic sneak attacks or stabs/cuts in the back against someone fighting someone else. More PS makes it more likely that you will finish off even slightly wounded enemies in this way.