Commander Riker is selected to participate in an officer exchange program that allows him to be the first Starfleet officer to serve aboard a Klingon vessel. Logically, you would think this would mean a Klingon officer would serve aboard the Enterprise, but since we already have Worf I guess that would be a redundancy. Instead, we get Ensign Mendon (John Putch), a Benzite who is very anxious to please. Mendon's arrogant-seeming personality is initially an annoyance before the story demonstrates that it truly understands him and allows us to sympathize with his different way of looking at things.
"A Matter of Honor" is TNG at its pro-diversity best. It's a perfect vehicle for Riker, providing an opportunity for him to exhibit both cerebral and testosterone-driven attributes. Consider the scene in Ten-Forward where he samples what seems like the entire Klingon menu: Here's a guy with a strong stomach and a completely genuine desire to learn about and immerse himself in an alien culture. Riker does his homework.
The scenes aboard the Klingon ship give us the first of the series' first-person perspectives into the workings and mindset of the TNG-era Klingons (which is to say the Klingons as allies rather than enemies). The story makes no mistake about the fact that the Klingons are a very different culture with very different values, as in the scene where Riker and first officer Klag (Brian Thompson) discuss Klag's father, whom Klag has essentially disowned because the father was unable to die in battle during his prime. The beauty of "A Matter of Honor" is its ability to find common ground between these divergent characters through universal qualities like food, humor, and self-integrity.
The plot throws a complication into this theme when the Klingon crew finds a substance eating away at the ship's hull and believes the Enterprise is to blame (for reasons that the plot is able to almost make plausible). The only thing holding this episode back somewhat is the stubborn, unlikely obstinacy of Captain Kargan (Christopher Collins), who seems way too determined to attack the Enterprise in retaliation rather than waiting to examine all the facts. But I enjoyed Riker's clever response to Kargan's unwillingness to listen, and his ability to play by the Klingons' rules in staging his power play. Riker's demand for Picard's surrender is classic.