To me, the RS is so much more than just a GT3 stripped down and more expensive. I haven't had the pleasure of driving either vehicle, but I am fond of the GT3 RS concept of having a "track car" and if I had the time, money, patience, and driving skills, I would love to own one.
I guess it's all relative, many will find the RS to be an overpriced version of the GT3, but to me, I think the difference is readily apparent and worthwhile.
Now, if only they put the PDK transmission into the GT3, if they say a driver will be faster with a PDK on the track, why don't they put the PDK transmission in the GT3? I just wonder if the PDK transmission can take the abuse on the track.