I love the dividers. Sometimes I only throw one or two bags in there and the dividers keep the bag(s) from sliding around while I drive. Especially helpful if any of the bags have delicate items in them like a laptop.
No ETA at this time. Ordered R1S with SR+ on 2/8 and still seeing "Purchase opens in 3-5 weeks." Latest from guide on 2/15 was "Your R1S is currently undergoing final testing and will then be prepped for transportation."