That music was one of THE reasons I bought the ST-TOS box-set. The music and the death scene make for one of the most gripping scenes of the entire series. It grabbed me before I experienced the death of a loved one and it grabs me even more since I have. Beauty and sadness make such a powerful force.
While I'm sure it wasn't the kind of relationship Kirk had with Edith Keeler, he never got to say goodbye to her, and probably feels terrible since he abetted her death. Here Kirk does get the chance, and isn't saddled with guilt. It's an effectively touching moment when their body language and the music coincide to indicate her passing. Adding the credits maintains the mournful moment despite the ship outro.
The Paradise Syndrome was my single favorite episode as a kid. And I've found that the Royal Philharmonic suite makes a nice encore to the OST, if you're in the mood for a longer presentation. When you're in that head space, too much is never enough.
Around the same time as the episode, Fried scored the doc. "Gauguin In Tahiti: Search For Paradise" which occasionally echoes this and Amok Time, although most of the score is different.
