<p>I realize people may disagree with me, but it worked for me and I got direct comments about how the rec actually helped me.</p>
<p>I think it just depends on who you have access to. Since I only worked in two labs, I had 2 PI’s. I got a great rec from both, but for the third my argument is I rather have another non prof rec from one of those labs than a random prof whos class I got an A in. It may seem redundant, but the recs they write are very different. My grad student commented a lot about how I would stay late to finish things when everyone left, and take over small projects on my own. He even commented how I fit well with the rest of the lab and the minute details of things I did, including my personalities when communicating with him. He even commented on the tiniest details. (The reason why I know this is because he let me read it after I submitted all my stuff even though I waived it)</p>
<p>To each is own I guess. I was just offering a possible alternative. I do agree with you, without the Dr. in front the rec may look weaker, but since I have the PIs from both labs praising me it is sufficient to prove that in the eyes of professors, they think I am qualified for graduate school.</p>