Ok, I finally got some time to spend on T500 so....
1) I went back to GT5 to run some cars on Le Mans 2009 that always reminded me...
...that some of my teeth have fillings when transiting the Mulsanne straight sections.
2) Then I ran the same cars in GT6 v1.09 on Le Mans' 2009 and 2013 Mulsanne straight sections.
3) And finally, I ran the Toyota TS030 LMP in the Seasonal, Test Drive and Single Player modes in GT6 v.1.09.
T500 settings for GT5 - no power assist steering, FFB 6.
(Same settings I used for 1 year in GT5 with T500)
T500 settings for GT6 - no power assist steering, FFB 4.
(Same settings I use for most GT6 cars except FF and some 4WD)
Rims: 458GTE, F1, (didn't use GT because static paddles are removed from my T500).
V.5 T500 RS running V.41 firmware, hard mounted to a very rigid 80/20 rig.
All cars used in GT5/GT6 were run bone stock, no driving aids, 0 ABS.
So, here is what I found;
1) Of the 4 cars I took for a spin in GT5/GT6, X2010, FGT, Mazda 787B, and Ferrari 330P4 '67...
...only the X2010 in GT5 produced any chatter close to what some cars produce on Mulsanne post GT6 v1.09.
2) In GT6, the X2010 becomes a beast once 7G is hit on Mulsanne straight sections (2009/2013)...
...even more cantankerous then the Toyota TS030.
The FGT, 787B, and 330P4 rock n' roll effects in GT6 V.1.09 seem as mild as GT5's on Mulsanne.
3) Wheel's chatter box behavior on Mulsanne straight sections (2009/2014) seems the same...
...on Seasonal TT, Garage Test Drive, and Single Player with TS030, did not test it online.
Conclusions:
As many of you remember, a short while ago there was a final seasonal event in GT5.
At the time, I remember how lifeless and monotone the wheel feedback seemed compared to GT6.
So my feeling now (yours may differ) is that FFB effect like Mulsanne straight is very exaggerated now.
Out of proportion with the wheel's rotational feedback which seems much lighter now.
That being said, counter-steer recovery seems to be more forgiving to me post V.1.09.
Me thinks PD needs to do some slight tweaking and bring a bit more weight back center-wise.