Two guys in my local HOG chapter just got Brightass lights on their Ultras. I've read about them here and seen them on the website but let me tell you --in person they are really really bright and attention getting. I'm ordering one of these lights as soon as I can.
What model did they buy? I have the BAL-1. I really like it but I have Radentz LED turn signals which I use as running lights and they are a lot brighter than the tail light. The BAL-2 is really bright but I didn't want to spend $400 on a tail light.