the middle ground...i second that option even though microTAS beat me to it (saying "i third that option" sounds plain ridiculous).
keep in mind the "audience" who will be reading your essays. if you make your research description too technical, you'll lose the reader. think as though you were giving a seminar to people who do not work in your field.
also, these secondary essays are just that...essays. feel free to make it somewhat narrative. It is OK to say "I". However, research is a team effort so try to use the word "we" more than "I".
finally, realize that the people who will be reading your essays will not sit down for hours analyzing it. they will read it for minutes before offering an interview. then when you go interview, the person interviewing you will glance at it before your appointment time comes. so make your essay an easy, fun, but intellectually sound read (and i can tell you from experience, this is not an easy task).
best of luck!
