I've been very happy with my Bikespeed RS unit.  I mean, just to reach speeds of a little over 22mph has been worth it, though my top speed, 'wicked-witch-of-the-west' cadence has been about 34mph.  
One concern:  Lately my module has been doing this thing where I hit Power Button and it only seems to turn on "half way"?  Cannot select any assistant levels, no lights - and the the Speedo doesn't show on the screen.  I've tried all kinds of things like turning it off & on , etc.  Seems to come back to life when it wants; sometimes sooner sometimes later.  Lately I have found the best thing to do is just let it turn itself off, then try again - usually comes to full function about 2 or 3x later.
The only factor I can think of is that I rode recently, twice, in EXTREME downpours, 20 minutes each time.  It seems to have started this new anomaly after those rides.  My B RS is tucked up inside the front part of the plastic engine housing.
BIKE:  2018 Sduro Trekking 9.5