I like most of them. Our family is scattered about the U.S., so we rarely get everyone together to keep up. Only some of us are on Facebook. I like to get the one page letter that tells me how old the kids are now and what they're up to. Fortunately, none of them send those awful doom & gloom letters or the "can you top this?" letters.
I write a Christmas letter every year at the request of my extended family. It's upbeat and humorous. I tell one anecdote about each kid (like, Christian won a blue ribbon at the Special Olympics, DD17 is active in her school's theater dept, and DS24 moved into this first apartment) and a little update on DH & I if something is new. I DONT write paragraphs bragging about all our various accomplishments. I figure if anyone really wants to know they'll call me and ask.