Which Professor should I ask? (Biostats)

[randomcat]

I am applying to Biostats programs this Fall, and I am wondering which of the two professors should I ask for a rec?

Prof 1 Pros:

-Took 2 Mathematical Statistics classes with him (got A- and A+, so there's a nice upward trend) 

-attended almost every office hour and asked questions

-full time professor in the statistics department; more experienced than Prof 2; probably has written many letters in the past

Prof 1 Cons: 

-can't write much about me beyond academic performance

 

Prof 2 Pros:

-Worked in his cancer lab for 4 months (doing survival analysis, power analysis, other statistical tests for grad students and their projects)

-can write about me in a working environment (ability to collaborate with others, etc)

Prof 2 Cons:

-assistant professor in genetics, so he has no renown in the statistics field

-can't write much about me beyond work

-not as eloquent as Prof 1 in emails (I don't know if this is a good indicator of how well he writes LORs); he misspelled my name once in an email

 

There is also the option of asking both professors. In that case I would have a total of 4 LORs. I'm not sure if that will hurt me (if 3 are randomly selected to be read, then there's a chance that my strongest LOR is left out) or help me. So any advice is greatly appreciated. 

Edited September 16, 2015 by randomcat

[fuzzylogician]

What will your other LORs be able to say about you? In particular, do you have other letters that talk about your lab experience and contributions? Along those lines, how much did you interact with Prof 2? Are there any tangible outcomes from your time in the lab - new data produced, experiments completed, etc? That is, can he write a strong detailed letter for you, or will it be vague? Same goes for Prof 1, what can he really say other than "random cat took two of my classes and got good grades, and often visited me at office hours to ask more questions"? Both are not the strongest contributions, so one question to ask is which one better rounds out your profile, given the other letters.