Glad to see a board dedicated to the R51.  Its got me very interested. I am CCP'd and currently have a Ruger SR40C for my concealed carry.  I love the gun, but its a little thick when carrying in my bike vest.  The R51 may be a good biker concealed carry and am looking forward to getting hands on.  I have very large hands and the Ruger w/ extended mag fits great.  The R51 looks to be a comfortable fit as well.  I also don't mind adding a 9mm to my arsenal as well. 

About me...I retired from the Air Force (2003) after 21 years, but as with most retired military, actively employed on my 2nd gig.