Lee, The folks at BCB/H2O wont steer you wrong. But, The decision is yours to make, and should be based on personal preference and knowledge,,,,so i do applaud your interest in gaining more perspective on both engines.The EFI will be slightly faster than the Opti, and will burn a little more fuel, but will also not have quite the resale value, or the warranty of the Opti. Basically that is it in a nutshell.So ,,,,,whatcha gonna do ? Just for grins,,,,you might consider a 175 Pro XS !!! Now things are gonna get interesting ! If i can help in any way gimme a shout, D.