Re: 90hp ELPTO vs OPTI
Personally, the HP is the same.
K.I.S.S. usually is a very good rule, the more complex the systems, the more things can go wrong.
The Opti is a much cleaner running motor, according to EPA mandates, and may well be the only units marketable in the foreseeable future.
So unless you are planing on boating on Emissions Controlled Waters, such as Lake Mead, I would Keep It Simple and go with the ELPTO
This is the one exception to the general rule of 'You get what you pay for'