I had a lot excellent service from several of manufactures (even big ones) in answering my questions, even if the questions where alway about relatively cheap equipment for less than $1000-2000 . Linn USA had really good telephone service. Naim, Quad and Lehmann were very good and courteous about anwering emails. The best service I have received so far was by Trichord Research (sister company to Michell). Graham Fowler (owner and head designer) is a really great person to talk to.
So far my experiences with the manufactures directly were always a lot better than with Dealers, although there are several good dealers out there as well.