Dear Comrade uses a plot device that is now common (if somewhat overused) in the TV genre -- the voiceover. In this particular episode, a Korean civilian named Kwang is secretly investigating the 4077th to determine the cause(s) of their unbelievable survival rate during first aid of wounded soldiers. And, of course, we are given clues to this observation: a close staff with the leisure to have a little fun in their "off times" so they can focus all of their seriousness when the attention phrase "Attention! All personnel! Incoming wounded!" is echoed.
We also get the "more of the same" interaction between Hawkeye, B.J., and Charles -- fortunately, I wouldn't ask for anything different from this group.
What was particularly interesting in this episode was the focus on the doctors' determination of a cure for a bad rash that seems to have affected multiple patients. I found it curious that the solution was simple while the doctors hypothesized complex solutions to the problem. This seemed somewhat out-of-character for the doctors, and indeed, intentionally so. This is their "flaw", so to speak. Their lack of knowledge about the land is what inhibits them from perfection (That, and you can't save everybody, of course). I thought this conclusion of Kwang's (and of the writers on the show) was particulary poignant and fitting.
Gary Burghoff did not appear in this episode, and this was notable. His humor to the show would have been nice and would have been an interesting characteristic to touch on given an outsider's view. Not to be.
Dear Comrade is not particularly funny or serious -- it's observational. Much of the observation was telling and smart, but the result is an episode that appears mediocre compared to the many first-rate shows that made M*A*S*H so great.