I am not sure of the answer, but I think it might be that the simple form suggests that the two actions substantially overlap in duration, but the continuous from is more appropriate to suggest that it completely contains the other action in time.
When you say: "I'm sitting here with a warm nostalgic feeling as I listen to the final master recordings," it suggests that the feeling and the listening have a similar duration in time.
If you say: "A nostalgic feeling comes over me as I am listening to the recordings" (as suggested in one of the comments), it suggests that the feeling does not last as long as the listening.
Specifically, the former suggests that the listening immediately led to the feeling and that the feeling will persist as long as you listen (even if that is not actually the case). The latter expression suggests that the feeling came upon you suddenly after the listening had already begun. Your action of listening is interrupted by a feeling.