Anything more specific? I would think that's a lot of engine for a 40DA, but if you are running long distances it might be worthwhile. Those are noisy engines on a smaller boat.
I've been on lots of SR520's, 540's, 580's, etc and many seem to have that spray where the swim platform 'catches' the passing water. Most that I've looked at are not perfectly aligned so its more prevalent to one side but I've seen it occur on both simultaneously.