Of course, people are blowing this all out of proportion because it's a new camera and a big purchase for any hobbyist. I wouldn't want a sensor that makes itself dusty, but it's not the end of the world to whip out a cleaning swab every once in a while.If the camera is going to collect that much dust after having spent $2000, I don't think it is "blowing out of proportion" ... it is very justified for people to complain about the sub-standard quality control of Nikon. People complain about Sigma & Tamron quality control for products that cost a quarter of the price Nikon is charging for D600
Sensor cleaning isn't hard to do nor is the equipment necessary particularly expensive compared to the cost of a full frame body. My main complaint with the D600 is the plasticky body and IMO inferior ergonomics; it makes me happy that I got a D700 while they were still in production.
People complain about third party lenses because of more frequent decentering, AF issues, etc, none of which have a fix as easy as just cleaning the sensor. BTW, I think both of the companies you mentioned have made great strides and I wouldn't hesitate to buy a lens from either one these days.
Roger from Lensrentals reported the dust "issue" falls to well within normal limits after 3000 shots. That's a few weekends or a single vacation for me? Hardly a big deal IMO, but to each his own