Chris has been having some issues with the NERS K-1-b/d model running through the Micro Engineering turnouts. With the Frog Juicer they seem fine, but without it's stalling. It also appears that it is 'sticking' through them to some degree, and when he checked the gauge of the turnouts, they are tight.
I've noticed the same gauge issues, although they aren't really unexpected in a commercial mass produced turnout. Some are worse than others, but don't seem to be problematic in actual operation. I'm guessing this is due to the amount of slop in the wheels, etc. of your typical model.
Anyway, here's a quick video (by Jessica), of my K-1-b running on DC through several turnouts. It also shows the difference between the track that had been cleaned about a two weeks ago and had graphite applied, and track that had been cleaned at the same time but did not receive graphite.