Hi
I have to sit firmly in the ‘I’m flying in a parcel of air, the ground can’t affect me’ school! Except of course in the case Bertie is asking about.
My feeling, for what it is worth, is that in ‘general turbulence’, it will not make any difference whether you are flying up or down wind. However when the turbulence is caused by standing wave type flow, there is a change in frequency of the turbulence due to Doppler Effect. Flying away from the source of turbulence the frequency will reduce - feels better, towards the source the frequency will increase - feels worse.
TeeS
P.S. Try letting the auto pilot do the turns - take the pilot out of the equation and you will see groundspeed just does not come into it!