I was no where near the level of potential steering effort you are but made the switch to power steering winter before last. Not because the effort was too high, but because the 20:1 ratio was just too slow.
I had actually planned to step up to a 16:1 manual box but had most of a factory PS setup already and figured that would be the cheap way to get a faster ratio. Then I got $200 off a Borgeson box in a Goodguys drawing so I made the leap and jumped right over the 16:1 ratio to 14:1 but spent more money than the 16:1 manual box would have cost me.
The 20:1 box was just too slow for the local roundabouts. Probably wouldn't have cared if they hadn't started putting those in.