Re: Advantages of an I/O?
I've had both and, as has already been said, there are advantages to each. Things I really liked about I/O - lots of power for the buck, nothing beats the sound of a V-8, engine format is common to autos so most people can easily understand how they work and do basic maintenance, unlike older outboards almost all older I/Os are 4-stroke engines.
When I lived in California and boated mainly in fresh water, I liked the I/O format a lot. I only had one that was a maintenance hog (an Olds 455 Rocket coupled to a mercruiser...but it was mighty quick!), but the others (chevy 4.3 and 5.7s) were not too bad. However, I moved to Florida where the waters are mainly brackish or salt and my experiences with the I/O turned sour. The salt water took it's toll on the drive, motor, and my wallet (yes, I flushed, maintained and everything else you are suppose to do). Sold the I/O and got a 18.5' no wood, dual console boat with a Yamaha F150 four stroke. This rig is perfect for my Florida needs. Runs reasonably fast (49 mph WOT gps), super economy, very quiet (quieter than most I/Os), smooth, no below the waterline through hulls to leak, easy to maintain, and it's darned near salt proof. I don't see myself going back to an I/O as long as I'm in Florida.
So, depending on where you run the boat, one man's advantage may be another's liability.