I have hull 309 of the 400 MK11
I installed a Max prop. I have used them on three different boats and am very happy. I am sure there are others as well.
As far as the 400 vs the 42. Believe it or not I believe the 400 out sails the 42.
As Crusingdad said the twin wheel is very nice. the 400 loves 20knot winds and just digs in. also the 135 is plenty and a heck of a lot easier to tack.