I've owned many 2strokes over the years.....but things move on and I do prefer 4strokes overall ...I find them much more economical... I like the quiet running....no oil to worry about...and if you've ever followed 2strokes at Sea for a period just hope you've enough Gee Gees to overtake
..( especially a twin set up)
The Trick with any engine choice for a RIB ...is to match the engine Size (Power) to the Hull AND loading expected Then prop it properly!... to get the performance your after
As for 2strokes v Four I can only speak from my experience
I've trialed/raced 250 HO g2 Tws strokes (on a LIGHTER Newer RIB!) ...against my own set up 6.8 RC with 250 Df in hole shot tests over a few hundred yards...
Result NOTHING in it!!!...not even 1/2 a Boat length.
Now that's a real world test!
"Hole shot" for me is paramount....but topping out at 48knots in a Heavy layup Ribcraft 6.8 isn't too shabby...I could possibly improve on top end....but Grunt and Holeshot punch may suffer.
Try some different combinations...but ultimately get the engine Size/choice/set up/prop/..RIGHT and you'll get the best out of you're chosen package regardless