Hi CAVU,
I can't add much to what's already been said here; I've got all the 'propaganda' on the engines and the 'pitch' from our area service rep with all the good things about the E-TEC but I haven't gotten my hands on one yet. The technology looks really good and I think that it will certainly enhance the two-stroke market.
The argument or considerations, however, remind me of the one involving horsepower...that is, more cubes or more engineering. In other words, you can get more horsepower by just installing a bigger engine (350 V-8 won't do it? Drop in a 454) or you can re-engineer your product with higher compression, better combustion shapes, better valve timing, etc; the fist is a typical American response, the latter more European. Which is better? Depends on what you want to accomplish...if I'm trying to pull a 34' 5th wheel I'd take the bigger displacement (also for the higher torque); for turning my lightweight sports car into a rocket ship I'd choose the lower weight engine and finer engineering.
I look on the 2-stroke versus 4-stoke decision the same way; what's going to work best for the task at hand? With the better (cleaner, more fuel efficient) technology in 2-strokes these days it's certainly a viable choice for high horsepower-to-weight applications. Engine costs, horsepower for horsepower, are not that much different now; the new technologies, like E-TEC, are not cheap to develop or manufacture.
If you've got a Bass Boat, a Ski Boat, or Walleye Boat or equivalent where maximum performance and speed are 'the' thing I'd say it's hard to beat the 2-strokes; and especially the new ones. For heavier all-round boats, cruising boats and off-shore boats I feel the 4-stokes have some distinct advantages.