I picked the E-Tec over the 4-strokes because of the power/weight issue. The 140 Zuke is about same weight but is not even close in mid-range torque that's nice to have with heavy loads and big seas. The E-Tec's are very strong running motors; BRP is sandbagging on the HP ratings by as much as 10%! Except for the very sophisticated fuel injectors and computer, they're basically very simple engines and should be cheaper to maintain over the long run. My dealer also sells Honda's and Yamaha's and said he's had fewer problems with the E-Tec's than either of the others, and I've had zero problems with mine in over 200 hrs, so I think BRP has solved the reliability problems of the early Ficht motors.
Understand that I'm not biased, of course!
The only caution I would have is to make sure you pick a good dealer with well trained mechanics. My dealer was ok with me doing all the rigging, which he was impressed with, but said it was critical that they purge all the air out of the oil system prior initial start, so he insisted on doing that. I think some of the low time powerhead failures they had when those motors first came out were due to some dealers not purging the oil system properly.