I own a Bluewater 355e (it is the white hull tower boat with triple 300 ETecs on the Bluewater web site) and have had the boat about a year. I have about 500 hours on the boat and have fished it in all kinds of conditions. The boat is super fast and the ride is fantastic. Recently I ran the boat directly from Elbow Cay, Bahamas to Pt. Canaveral, FL in a 15 kt north wind. The Gulf Stream was ugly, we ran at a comfortable 36 mph and I never had to touch the throttles. The guy riding with me kept saying "I can not believe this ride and we are not getting wet this boat is a machine". It really is a rock solid boat with amazing performance.
The guys a Bluewater have designed and build a great boat (and I have fished on almost all the upper end center consoles out there) lots of storage for tackle & rods, hugh live wells and fish boxes and an amazing amount of fishing room. They do a great job rigging and stand behind their product.
Top speed is a touch over 60 mph (with about 180 gal fuel, 3 guys and gear - flat water) but with the wrong props. I am running 23" 3 blades on all 3 motors. My center motor was running about 3oo rpm higher then to other two so I can see I need more pitch in the center which is common on triple motor set ups. I still have a bit more experimenting to do with the props.
I cruise between 37 and 41 depending on load and wind (I do have the tower and buggy top which adds drag) and get a hair over 1 mpg. I ran several other prop set ups and have seen 1.2 mpg at that speed. My motor tech believes I should end up a little better then that when we are done messing with props.