riemann11

Hey everyone. I just submitted my app but now I have decide which letters I want to use and I was looking for some advice. I've asked four people and I'm pretty sure they will all get them in on time, so now I have to decide how I want to rank my letters. For sure I'm going to use my current research advisor and a professor from a summer REU, but I'm not sure who to choose between my last two writers. Letter writer A is a postdoc who was in charge of my project at the REU over the summer. This research was similar to what I wrote about for my research proposal. Letter writer B is an assistant professor I took a class from (though the class does correlate to what my research will be on). Both know me well and I think both will have nice things to say, but the content will be different (A will talk about research and B will talk about my classroom performance). So, my dilemma is, should I use A's letter, which focuses on research, but may be redundant since I already have a letter from that REU? Or should I use B's letter, which only comments on my academic ability? Also, does postdoc vs professor make any sort of difference??