I generally swap out skewers for good quality non-QR's, as I always carry the allen wrench needed, anyway (fits seat post binder, calipers, etc). It adds $20 to the cost of each bike, but is good risk prevention.
Some skewers that come with aftermarket wheels are simply built for weight, not strength.
I also had a higher-end set of hubs that came misaligned on the axle, and prevented good tightening on one side, you could check that.
I've seen the QR skewer cams get stuck, break, and fail on numerous aftermarket wheels.
I won't mention any names, like Bontrager or Mavic, but it could be related more to the care/maintenance of the bike than the skewer quality.
The cheaper non-QR skewers are very susceptible to the threads stripping, so I'd be careful with those.
Use both sides of the towel.
1985 Raleigh Racing USA - Competition (honoring cehowardGS)
1988 Centurion Dave Scott Ironman Master
1989 Centurion Dave Scott Ironman Expert
1989 Centurion Carbon R