As encouragement to all, I have two main things to say: Yes, there are people out there who read these letters of recommendation (in fact, it's part of their job). Thus, your work is significant and worthwhile. And remember, an individual letter writer is but one voice among several singing in support of an applicant. Therefore, each letter need not describe its subject completely; rather, it need only give an informed perspective from within the context that the author and applicant know each other.
Last Friday, I attended a one-day conference hosted by Cooper Medical School of Rowan University, the new allopathic medical school in Camden. We Philly-area pre-health advisers like to get together every January at a different health professional school, engaging in dialogue about timely professional topics, hearing updates from Admissions deans, and generally comparing notes . . .