Sram DD3 and BBSHD
I use a Sram DualDrive system with my BBSHD ebike, and it works great! I bought my DD3 from a different seller than Luna (I didn't know Luna sold them), and it was far more expensive and only a 7-speed. I have no problems after 400 miles on it. I'm fairly heavy on the throttle, too, so I know that these things can handle high power levels. I have a torque arm on the axle for the IGH, because it twists against the dropouts and I'm afraid that at 1500 watts, they'll snap.
-I have amazing gear range, just like before my bike was a mid-drive and had a front triple chainring.
-extremely strong, it has held up under the full might of a BBSHD for over 400 miles with no issues
-great for ease of riding, I usually leave my chain on one gear while riding and shift only with the IGH, it's so convenient when riding around the city
-excellent shifting speed, I never have to worry about how long it's going to take for the chain to get onto the next sprocket, the IGH shifts instantly and even while stopped
-I had to buy a second gearsensor for the IGH
-It makes an annoying clicking sound when the IGH is in its top gear, no matter the power being put through it
-Shifter is a little awkward to use
-I use a torque arm because of the twisting force the IGH puts on the dropouts when in 1st or 3rd gear, it took up valuable space, forcing me to come up with a new mounting method for my fenders.
All in all, I highly recommend the Sram DualDrive system to anyone who is unsatisfied with the current gear range of their ebike. This thing can take as much power as you can throw at it, and still works like a charm.