I just replaced the control valve with one of the adapters. Like Bob said, if you have meaty front tires it can get a bit cumbersome on tight turns, but I didn't find it unacceptable, just a little rough on tight turns. Although admittedly I have a higher tolerance for such things, I was considering a new manual box with my old BF Goodriches on 7" rims.
When I put the M/T skinnys on the front, effort was drastically reduced. I already had a new Flaming River power steering box, so I didn't want to drop the money for a manual unit. With the skinny tires it's not an issue at all to me.