you are referrring to 300XS Optimax?I love my single 250XS for everyday boating.I hear my 250 is conservativly rated and is more like 268hp and the 300s are right at 300hp from what i hear.My 250 has redlined at 6400,but i hear they are done making power at 5900 to 6000.i think the 300 redline is 6000 or 6100.The 300X will rev to 6800 and is a little stouter IMO.The advantage of the Optis is they never have visible smoke are quite and the mid range fuel economy is awesome compared to conventional 2 stroke EFI.I have personally got seven mile per gallon at slow cruise speeds and my goal is to break 90mph with the 224 Stoker.I have seen 87mph with a 26 ET lightnin and am waiting for the 28 Pro ET four to arrive,if Merc will ever release them :yuk: they only announced them last February at Miami boat show