The 300’s are plenty - depending on how YOU will use the boat. I had a 2003 330 - with 225’s. Ask anyone who has NEVER owned the boat and they’ll tell you it was underpowered. For some that could be true. However, I am an experienced boater in most all conditions, ran that boat well offshore many times in various weather, cruised it, etc. and it was fine for a 33’ express boat. I never did SKA type tournaments - but I did plenty of shark tournaments - so overall speed wasn’t the issue. With the 225’s she planed, cruised, handled just fine. I cruised around 29 MPH at 4400 IIRC. My buddy ended up getting an 06 with 250’s. Performed IDENTICALLY except for top speed. He loved that boat and used it as I used mine. By the way, mine had no thruster - some will say it is necessary - nope…nice to have yes, necessary - I never had an issue. The 300’s will push that boat just fine unless you want a fast boat that cruises in the 40’s…..Then it won’t be enough for you. It’s all how YOU use your boat but twin 225’s never put me in a situation where I wanted/needed more power. It’s all relative….In 5 years when 600 HP outboards are the norm people will say twin 425s are too slow……..