You don't really have much say in either.
The MSPE can be several pages long depending on your school and the amount of graphs/info they attach to it. We were able to see what was written about us, and I saw one interviewer flipping through all of the pages of graphs at one of my interviews. I think the typed up part about me was about 1.5 pages that summarized what I had done in college and med school.
LORs, I bet the writers say what they need to say, but them concise because interviewers read through a bunch.