I'm in the exact same dilemma....Opti/E-Tec!
The facts are the following:
The new E-Tec seems to be more economical than the Opti, as far as the running cost is concerned (e.g. 300 hrs maintenance free, low consumption), and seems to be more reliable than the older Evinrude models in general (new materials, robust, etc.). In addition, they, as well, come with a management system similar to Mercury's SmartCraft. Hence, since you are talking for 2000 hrs/year, the E-Tec may prove to be a smart choice. The noise, however, seems to be a bit louder than the Opti. Finally, the new white, saltwater engines are a beauty!
The Opti is nothing special as far as looks is conserned. However, it has been around and tested successfully, longer than the new E-Tec. It is powerful, economical, and more simple than the E-Tec. Also a bit more 'dirty' (2-stars).
Finally, my opinion is that a 4-Stroke, together with the higher price, will by no means be cheap to run. If the 2000hrs are true, then maintenance cost will be way above 2-strokes.
I'm probably going for the Opti myself, 'cause Evinrude is not very popular around here, mainly because of the old problems. Hence, hard to re-sell......