rospy.Publisher: what's a good choice for queue_size?

edit

The queue size is a balance between latency and completeness. If your usage only wants the latest data a small queue size is appropriate. If your application would rather have more complete information a larger queue size is preferred.

Note it will only be an issue if your topic backs up. Another consideration is if the publisher will be pushing multiple messages close together make sure the queue is big enough to hold the whole batch if you don't want losses.