At FL250 you can be just in the really turbulent outer edges (isotachs) of the jet stream. Difficult to see and a interesting ride if you encounter this phenomena.
I have driven TBM700 after viewing one at Farnborough and the guys from Tarbes would not let me go unless I had had a test flight. Competent aircraft although the model behind your excellent report and given a million dollars an excellent choice.
My instructor at Humberside drove King Airs and MU2's professionally before and after his training business and he was a very wise old bird with 25000+ corporate hours. The MU2 was his weapon of choice but with that wing - you had to be super current. Just to emphasise the attention to detail - he ferried one from USA and the wrong grease was used in the gear that froze up en route. Slightly nervous approach into Reykavik with 0 greens. There are so many aspects one has to consider with HP a/c at high altitude.
Sorry for the drift Above the Clouds.