I rented an F800St in Europe last year and had an issue with the bike stalling after coming off a long stretch at speed. Pulling off the hiway after being at speed for a while, it would stall during downshifts as I pulled into a rest area/offramp/viewing area etc. I did not like that. I was not sure if it was just that bike as it was a rental or what.
I rented that bike as a trial of that engine as the GS was not out. I liked it other than that issue. Good power and all, not much vib except through a narrow rev range.
It never quit in gear though, it was when I pulled the clutch lever to downshift that it would quit. I would hit the start button on the roll and it would fire up again, but then quit at the next downshift again. Anoying to say the least.