To me it looks like the engineer's power is that they're good when team loses, but their weak point is that they totally suck when team wins.

That's pretty accurate, actually.

An engineer rocks at coming into an area and taking a control point.  I have so many knockbacks that I can keep an opponent out of the control point the *entire time* it takes to take it over.  So I flip a control point and run away (or die), and then do it again on another point. 

I can also hold a point very well against a small number of people, so should the opponent split into two, I can keep them from taking the point for a few minutes, give my team time to come over.

If the team sucks, then I'm spinning my wheels but getting to look like a rock star.  If the team rocks, then I kinda just pew pew things and don't really get to shine. 

Yes - Incredibly low score for the rest of the team.  I liked the Engineer and may play one but they are definitly a background class, really great if you have team support and really useless if you don't.

yeah engineer imo still needs work their weapon sets kinda suck and are one trick pony currently.

epic Wiliam and epic Martin fighting each other... some games just want to see the world burn