Would a 4th LoR at this point in the game be at all useful? Would it bolster my application at programs that have granted me interviews already? I just got my ICU grade back and the course director (sort of a bigwig, always part of an NIH trial or two) wrote some really nice things in his eval. He attended for a week during my month so he actually does knows me. Basically, I'm pretty sure it'd be a strong LoR but I'm not sure if programs would care or if it's all about the interview at this juncture. Thoughts? Comments? Personal attacks?