Just what I needed to know!
Both the "Leisure" and the "Endro" are 2-stroke models. I worry bit about the fit of the Leisure model in the locker because the shifter is out in front of the engine. The 9.9 and the 15 Enduro are the same block and drive train, so if the 15 fits, the 9.9 will as well.
I have been very happy with our old 8HP, and hardily ever run it wide open. I had been thinking that anything over 9.9 would be overkill. But with the 15 and 9.9 both weighing the same--and costing about the same--I might just go for the overkill.