Most usually included in Christmas cards, round robin newsletters are best avoided. They are impersonal and can seem boastful, especially if they are a rambling litany of the family's achievements.
Recipients may, justifiably, feel that they have no special role to play in the sender's life. As such, round robins can actually do more harm than good.
It is infinitely preferable to include a short, personal letter with cards to friends or relatives who are rarely seen.
If this is just too much to contemplate in the pre-Christmas panic, resist the temptation to send out a circular. Just add a brief note in your card saying 'let's catch up in the new year', and make a note to remind yourself to make a phone call, send an email, or even write a brief new year's letter.