In general if the windspeed is 30% of cruise, I would expect more turbulance down low than at 20% (i.e. 50 knots rather than 30 knots). However, I have never noticed that bumps on a 30 kt day are worse when I slow down. The physics say the particularly hard bumps should be softer at a slow speed (because the wings stall a bit and you can't get as high a G load).
However, in my flying, I am most likely to be slow at less than 1500 ft (fitting into circuit traffic) and fast at altitude, which means it is typically rougher when I am slow than fast - but this is down to altitude not speed.
None of this has anything to do with the practicality of flying at best range speed and how this changes with head/tail wind.
your preference for headwind may be that it gives more time to think and therefore you have less pressure. With 60knots of wind I find it easier (other than the frustration) to have it on the nose as everything that relates to the ground happens at half speed relative to the wind from behind.
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A further thought, the main cause of turbulence will be a change in local vertical airflow - and this will happen over a certain distance. The faster you are going over the ground the higher the frequency of these reversal (you should have more g reversals per second). this may be perceived as less comfortable or being more beaten up (head bashes per minute goes up but the total number of head bashes remains constant)
Last edited by mm_flynn; 27th Aug 2009 at 12:14.
Reason: further thought