Unfortunately, I cannot find a long term road test by car and driver for the GS350, but I can tell you that my 08 GS350 AWD had more than 5 unscheduled visits in less than one year. It might have been my bad luck, the other 4 Lexus I had owned in the pass have been very relaible.
Did I say TL in my last post, I mean the RL.
You are correct, the GS in the test is a non F Sport and the A6 had the 19" sport package. Its a bit surprising to me that a non sport packaged GS ride stiffer than a A6 with the sport package. The A6 SP rides pretty stiff already, I hate feel how stiff the ride is on a F-Sport equipped GS. I think Lexus might have gone over board a bit with the suspension on the GS, but I will reserve that comment until I test drive the GS350 next week.
Yes, AWD Lexus sedans have a unfavorable reliability history, many of us are well aware of this. Other and most Lexus products have done much better. RL is just a failure, complete sales flop btw.
I heard the GS is at dealer now. I'll drive one soon. My taste tends to favor somewhat firmly suspended cars, probably result of owning several Porsches, etc. My IS350 equipped with sport package is on 19's with F-Sport springs (Eibach being the OEM supplier of these Eibach 350 progressive rate springs), summer tires (T1R) so the effect is very BMW sport package-like.