Attachment Parenting International doesn't endorse a specific brand of bed rails. The most important thing we emphasize is to keep safety in mind and do your own product research before making a purchase.
Bed rails can certainly increase safety, but it is important to note that there have been some unfortunate cases where babies became trapped between the bed rail and part of the bed. This can happen in a family bed or a toddler bed, so it is imperative that the bed rail fit tightly and securely to the bed; even a small gap could pose a risk to your child. Another thing to be aware of is that your child may try to crawl over the rail and could possibly become injured by a fall.
Many families find that taking their mattress off of the bed frame and placing it on the floor eliminates a lot of worry. Should a child wake and decide to crawl off the mattress, it would be inches from the floor, lessening the severity of the fall and making it easier for the child to master safely getting on and off of the bed.
As with every parenting decision, use your best judgment. Since every family shares sleep differently, only the parents can decide what the safest option is for their family.