By PAUL BERTORELLI

S-TEC’s IntelliFlight 2100, left, is an easy-to-operate digital autopilot designed to integrate with Avidyne’s new Envision EFIS.

If avionics manufacturers really listen to their customers and we have no reason to believe they don’t they’ve been hearing a not-so-subtle thrumming sound of impatient fingers tapping glareshields, anxiously awaiting the arrival of real glass for aftermarket installations. Garmin primed the pump last summer with its announcement of the G600 display-only version of the G1000 EFIS suite, but it hasn’t exactly been introduced yet.

That leaves Avidyne one down in the uncertain but inevitable hopscotch toward glass systems even the owner of a 30-year-old Bonanza can afford. In October, Avidyne inched closer to that reality, but for the time being, only King Air owners need apply. Teaming with autopilot giant…