I would agree.. Quality over Quantity. We sent in only an overall cover letter, and a relationship proof letter from my wife in her own language (translated, and notarized), and the rest of it was the forms and supporting letters from my boss and relatives. We have been together for over 5 years now, and married for 3, so we have over 8000 pictures which we had to chose from.. to me, 100 was far too many, but I could not decide which ones to trim, so they got bundled and sent off.
It is my opinion that the more proof you include (especially written) will only delay the application especially if it's full of filler.. Why waste the VO's time reading through a novel when they only need a detailed summary?