The original engine on my Ranger was an Opti Max. It gave me great service for a long time...I put a lot of hours on it until I finally wore it out. When the power head finally did give out I put a new fully dressed power head on it and had nothing but problems.....but the new powerhead was one of the famed opti pop years of 01, 02 and 03 which had the class action suit on them.
I put a new Etec HO on my boat this past June and when I put my boat away this winter it has already clocked 260 hours...no problems.

Fuel milage I am getting pretty much the same as I did on my Opti....very little difference. Oil consumption is better on the Etec. Low end torque on the Etec is better than my Opti was (I kept the same prop and set up was not changed). Don't know about top end because I do not run my boat at WOT. My engines have to last and as much as I am out there running WOT would definitely shorten the lifespan.