i think the trick is keeping it light up front. its a narrow entry - great for running into the waves. i put 9' long lifting rails running from the stem aft about 12" below the waterline to give my bow more lift, about 1" wide. i picked up a little speed from it as well as it lifts the whole bow a little higher, and it makes it alot drier. keeping the weight aft will help. so far, the qsb is a great little engine. at times i wish i had put the qsc 600 in, but frankly the boat runs so nice at 21-22 knots in all seas, that it would be hard to justify the extra weight and fuel. I think the new 6.7 qsb will be great for you, but i havent seen the comparison to the 5.9. as will all these high rpm engines, they make most of their power in the last 400 rpm, but I can't think about running it that hard. I grew up commercial fishing in alaska, and a high rpm engine back then was a 3208T Cat that turned 2600rpm, so its hard to run these engines much above that.
I will try to get a video of it running at cruise. good luck, and let me know if i can help.