The high output relays were also silver contact, gold-plated but they were considerably less sophisticated, since they had to be able to withstand several amps of switching current with high power amplifiers. Later, the company produced a commercial version of the ABX tester for sales representative use and that product has received a lot of comment (mostly uninformed) on the internet:
A friend, Rob Schlette, did a well-informed article about some software based ABX testers for TheProAudioFiles.com ), Audio Perception and ABX Testing, a while back and that's a pretty good place to start your own thoughts about the subject.
A few of us--Jake Swanson (S&M Audio), Aaron Hodgson (McNally Smith Record Lab Manager), and I--recently revitalized the ABX tester for use at McNally Smith College of Music. I haven't had a chance to mess with the new unit, but I'm sure it will raise eyebrows and piss off "professionals" every bit as much as did the original QSC product.