Strange,
I truly believe that if anything, it couldn't hurt and at best, it could really put you over the top in going to the place you want. I am a fourth year who is just finishing up a three month project with the OUTCOMES RESEARCH Instutute under Dr. Dan Sessler. I not only got to be involved in several interesting studies, but I also got to know nearly all of the faculty and residents at U of L fairly well. It helped me when I went to ask for LORs and they were also very willing to help me edit my personal statement. So for me, the process helped me in numerous ways even though I had to use most of my 4th year elective time. I am currently working on my first research paper, of which I will be first author . I would highly recommend getting involved with research based on the experience I had, especially if you are wanting to match at a university based program.
Hope this helps,
HOG