I prefer a touch more preload with the passenger as the bike turns in easier. In the beginning I only adjusted the rear, but now I also did the front and thus braking improved because there is less pitching from rear to front.

 

I adjusted the rear and aired the tires up a bit when I had a passenger, but didn't like it at all.

I'm gonna try leaving it as is and see how it feels, hopefully it'll be better.

Taking the woman to her class tomorrow, so we'll find out, haha.

 

For the road, tyre pressure should remain as per the book with/without passenger (36 Front / 42 Rear IIRC).