definitely perked. I wouldn't mind it replacing the useless spit14
+1
You're greatly overestimating the Spit XII. Perked in mid-war, sure. Late war, why?
When the RAF was testing the Merlin 25 Mosquito VI they used a Spitfire XII as the opposition. The Mosquito was able to accelerate from a fast cruise and escape before the Spitfire XII could get into firing range.
The Griffon III and IV produced, IIRC, ~1,700hp, not the 2,050hp that the Spitfire XIV's Griffon 65 produced.