“…looked to have problems with turbulence …”
Not surprising with the additional side area forward of the c.g. – some relaxation of the directional stability perhaps?
The R.1 mods are aerodynamically neutral - added ventral fins combined with vast amounts of extra electronic jiggery pokery aft of the cofg mean it handles exactly the same as the Global Express.
On the way home on Saturday the R.1 managed to confuse many spotters at Newark's cockpitfest with a suspiciously well timed orbit of the museum during the Dakota's display! (well separated by height before the flight safety stazi on here start)
Big thanks to the crew for that one. Seeing commited spotters having to resort to flicking through Janes - priceless.