I'm no expert, but I think 4 blades on that size boat with TRS drives is looking for trouble. Think of the Mirages slipping like slipping the clutch on a car to get it going as opposed to just dropping the clutch. I would think the 3 blades would be much easier on the drivetrain.

I was going to let a buddy use a spare set of mirages on his 42 excalibur eagle. Thanks for starting this thread. Looks like no problem to install on the trs'.