I run Mercury motors. Only problem I've had since '96 is mild starter trouble.
I pulled it apart and sanded it, toss it back together and new again. so that makes it 13 years old, used 150 days a year at the very least, and I run it very hard - never broken anything.
about faster, I dont know about that. that has to do with size of motor, weight to power ratio, pump or prop, pitch and depth of the screw, way too many variables so I can't be convinced one is faster than the other without everything being equal and using two motors of exactly the same size running on the same fuel, and then testing them both.
At 2/3rds throttle with my 90 horse Mercury on my 18' sled I pass cars on the highway/freeway.