I've been using the BDL CS-34a compensator for 15,000 miles on my '13 Ultra FLHTCUSE8, and it works great.
After only 5000 miles on my '13 Ultra, my compensator was shot. It would clunk when starting and shutting down. Every time I opened or closed the throttle, there were driveline lash/rattles and clunks, and it sounded and felt like the driveline was falling apart. It really was affecting the enjoyment of riding, and I knew from my previous bike (replaced 2 compensators in 20,000 miles) it was the compensator again.
Instead of putting in another POS Harley comp, I found BDL, and decided to try their comp. Installation was a breeze. The unit was much lighter and simpler than the Harley unit, and it appeared to be very robust. And, it was significantly cheaper than the HD compensator. After I installed it, the difference was amazing, and it has been working like a charm since. The clunking and sloppiness disappeared and the driveline has been consistently smooth and quiet for 15,000 miles. I can't say empirically that the driveline is tighter and functioning better, but it sure as hell feels and sounds better. And so far, it has lasted longer than any compensator I've had on my last two bikes.
Until Harley redesigns their compensator, I think it is a waste of time to throw money away buying their current lousy compensator design. The BDL CS-34a is a much better alternative, IMO.
Dan