IMO, 997.2 Carrera S with race buckets, PDK, LSD, SC is a very reasonable car which would be very good both at track and DD.
On the other hand, I had driven R8 V8 and I like it better than my ex-911 Carrera S.
Both the interior quality and handling behaviour are better than 911, IMO.
So when you put the R8 V10 into equation, if the money is not important, I would have choosen it over 997.2 Carrera S and 997.2 GT3 (since you are planning to have only 2 track days every year.)
Also there is one more thing and that is, I don't know how you drive, the test numbers are coming from semi-professionals drivers and some cars are more difficult to drive faster (such as an F360 Modena or 997 GT2) than other cars (such as E46 M3 CSL or Nissan GTR).
So even if the Turbo is faster than R8 V10 by little, I believe R8 has better manners that will give you more fun; especially on spirited driving instead of track days.
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ONUR
09 Audi TTS Ibis
07 997 Carrera S / 05 M3 Coupe / 03 M3 Coupe / 96 M3 Coupe EVO (ALL BUT HISTORY)