The guest casting of MSW was always a tremendous strength of the show. Film and television stars, many from decades past, appeared in many episodes; and actors who were not big stars, but were still highly talented veterans, also appeared.
In this episode, guest stars had appeared in six different, long-running series! I think that may stand as a record for one MSW episode! Plus there were actors who are always a pleasure to watch, such as Peter Haskell and Ken Swofford. Some reviewers have been tough on Jeff Conaway's performance, but I thought he was good. My only criticism would be, to me he looked a touch too old for Genie Francis, who was only 24 at the time.
In some ways, I think MSW could be a challenge for an actor. The show had a very particular tone, which involved often infusing the roles with a humorous undercurrent in keeping with the show's spirit, but maintaining dramatic tension and enough credibility. Not so simple for the actors! But the great old pros such as Haskell and Swofford, and others here, make it look so easy. It's not.