I read on this site that a user had problems with the several Ridgid 12 Miter saw alignment.
I bought a Ridgid 12 sliding compound miter saw and noticed that the saw plane and the sliding rails were not aligned and of course this is built into the casting and cannot be adjusted. I returned to Home Depot and they allowed me to open several more boxes to check with my dial indicator. They were all bad and most worse than the one I bought. They gracefully took it back and returned my money.
Later at several wood working shows I dialed several other brands, Makita was consistently accurated within <0.001" in a distance of 8". Hiatachi was next within <0.002", and similar to Bosche, over the same distance. The rest were worse but no where near as bad as the Ridgid. I was very dissapointed because the Ridgid has some very nice features from an operating point of view. They are machining green castings or their boring jigs are not set up accurately. Hope this is info is of some use to others.