I would have liked to see the PD-8X thrown in the mix. I have bikes equipped with PD-8 and a PD-8X hubs and notice drag on the PD-8X equipped bike much more than the PD-8 equipped bike. Enough so that I often wonder if there's an issue with the PD-8X hub. I know there's nothing scientific about it but when spinning both wheels by hand the PD-8 will spin several seconds longer than the PD-8X hub. Otherwise, I am a big fan of dynamo hubs...