Never had an optimax but do yave a 2005 90 horse Merc , it's been ok , have had issues, I have a 250 Evinrude on a bigger boat and a Yamaha kicker , I like Evinrude/ Johnson the best and can't beat my Yamaha kicker have had two other mercs both were brand new when I bought boats , just not a real fan of Merc ,but that's just my preference