GT3RS has up to 345kg downforce which obviously the 911R does not. The new rear diffusor on the 911R helps a bit.
So 911R pursists streetcar.
GT3RS trackdaywarrior.
Sadly no MT in GT3RS for now but having stated the downforce info I'd go for a GT3RS anytime.
And I'm not a purist by Porsche standards, also fine with me.
I'd take a RUF SCR 4.2 over a 911R as well
New car: 964 bodywork 4.2 litres NA, 7cm longer wheelbase for stability.
I love it!
Cheers
Robin