It's a step up from the sterndrives in every conceivable way. They are more reliable and faster. They also dramatically improve handling because they are actually meant to operate as a surface drive. Many manufacturers are now mounting sterndrives with such aggressive X dimensions in order to squeeze some more speed that they are virtually running in a surface drive mode. This adversely affects handling and general dynamic behaviour because Bravos, even with Sportmaster lowers are not meant for that. Not even SSM6 is meant for that. Arneson is not exemplary but it is much better than any sterndrive in that department. They can also be cheaper. If you are running around 700hp with a gas motor, you would need a SSM6 unless you're really looking for trouble. This damn thing is expensive. Instead you can run the new Arneson ASD6 which is a lot cheaper than the Speedmaster. In terms of speed over a Bravo sterndrive, I would say that the gain is more than 6 mph. For example, a Hustler 388 Slingshot (whose transom you can see in the OSO side column ads for Arneson) with twin KE 675s and ASD6s ran 110 mph. I doubt it would run 104 with Bravo or SSM6 drives for two different reasons. Bravos are penalized by the fact that they are not surface drives, their thrust is at a greater angle meaning a loss in efficiency. A SSM6 on the other hand is built so heavily that it probably takes 50 or more horses to move the cogs around. Arneson is much more efficient from that point of view. Next time you go to a boat show, find a boat with Arnesons and a boat with SSM6s and try to spin the prop and you'll see what I mean. It takes a lot more energy to spin a SSM6. I've experienced all imaginable drives: Alphas, Bravos 1, 2, 3, Volvo DPs, Speedmaster 3, 5, 6, Pulse Drive, Sea Fury, Levi Drive, BPM, Arneson, Trimax and while Trimax remains my favourite, Arneson is up there and I would never go from those surface drive systems back to sterndrives.