Two trannys so far and some parts. First went at 1800 miles only took three power shifts. The second tranny the reverse seal plunger valve went after about 300 miles in it, just backing it up. I upgraded the plunger seal myself(parts sent from NESCO)
I now ride like a wuss, no power shifting , absolutely no more drag strip running, no accerleration in second gear oops I mean over drive, no backing up a incline , no pushing the reserve button on and off , running two tranny coolers to keep seals and soft parts cooler and using mobil one MX4T.
5000 miles later after riding like an old lady tranny still works OK.
You won't get too many responses on this one, it's been tried many times before to get an accurate count.
Don't let me discourage you from your bike, just be aware the tranny is the weakest link and you must realize you are never going to power shift it or accerlerate hard in overdrive. If you do you will be splitting the frame and pulling the tranny.
mine tranny was a 2000 and was upgraded in 2003 to that standard.
Let me conclude with this: despite the tranny's short comings it is still a blast to ride and I enjoy the rush it provides.