I have the 280BR which is very similiar except for the cuddy portion. The boat runs top end at 57 mph. I have had the boat in a 4 chop running at about 25 mph with no problems. With the weight of the boat you will find it to be a nice smooth ride and very enjoyable. If you have more questions please let me know.
The BravoIII does wonders for time to plane and holeshot as expected, but what I am suprised by is the comparitivley poor cruising speed - isn't this where BIII's should really shine?
I imagine the 1000# of weight can be explained by the Arch as mentioned, plus the addtional weight of BIII drives and closed cooling on the engines.
What this doesn't explain is how the 2002 BR is almost another 1000# heavier and is 7MPH faster than the BIII boat. I read the comments of single vs. twin engine but I can't imagine an outfit like boattest.com making such a rookie mistake.
The speed that I posted is using GPS and using the trim and drive tabs to the best that it could be done. The weight difference is not from the arch but motor and drive options. I have owned mine for a few years and know the boat inside and out. Wish that I could have got the 8.1s to get over 60 though.
As far as best speed to RPM ratio it is at 3800 RPM's, this gives a speed of 43 MPH when properly trimmed. I know you burn more gas but I also think you want MPH to be higher than RPM for best performance.