The R-13 is what I have been playing since the first day I held a clarinet in my hands. Buffets are famous for their full, dark, resonant tones. I have yet to hear another clarinet whose characteristic sound I liked more. Along with its famous tone, the R-13 suffers from uneven pitch. When shopping for an R-13, always test these intervals with a tuner.
Some instruments are worse than others.
In my experience, shopping for an R-13 is like trying to find a good reed in a box of ten. Of course choosing a poor reed doesn't set you back two grand. Buffet takes top honors in my opinion for their professional bass clarinet. Normally, the stock mouthpiece included with a new instrument is a throw-away that just takes up space in the case. However, the mouthpiece that comes with the Buffet bass is unquestionably the best bass mouthpiece I have played.