I had it on my Ducati 1299 with the Termi Relevance slip ons. When I installed the Vandemon Undertail exhaust I had my ecu flashed by Vcyclenut. I will have the Rapid bike plus the rapid bike my tuning on both BMWs. There was never any issues. It worked great. The unit self tunes and learns how you ride. It adapts to how you ride and give you power when it know you need it. The only reason I removed it from my Ducati was because I found a thread how Vcyclenut made a map for all 3 rides modes designed just for a 1299 with a Vandemon undertail. And you can use that same flash if you have the Akra undertail.
Here is a youtube link where the guys riding a 1299 explains it really well. As well as talks about what he feels as the bike is learning. Ive sold a lot of rapid bike and never had any complaints. Go to the 2:30 min mark. The first 2:30 mins is useless information. If youre interested shoot me a PM for a price.