I owned Adcom preamps, CD players, and amps for a number of years, and used it with several incarnations of Vandersteen speakers (2Ci, then 2Ce, and eventually 3A's). I found Adcom equipment to work very well with Vandersteen speakers.
I have also helped my son assemble his system, which currently consists of Vandy 3A's driven by an Adcom GTP-760 pre/pro, Adcom 5503 amp (for the left, center, and right speakers), and his old Adcom 545-II amp for the rear surrounds. His system sounds very good, and since we were able to get some excellent buys on used gear through Audiogon, it has a high price-to-performance ratio.