Rtn1, I don't have access to those measurements. Am I correct in assuming that those measurements are suggesting 150 Watts per channel into 8 Ohms and 200 watts per channel into 4 Ohms? Do those measurements specify that the first 60 Watts into 4 Ohms are in Class A, or are you assuming that they are?
Again, though of a different design, Nelson Pass's Class A/AB Threshold amps provided the first 20% of out-put into 8 Ohms in Class A and the balance in Class AB, into 4 Ohms the Class A output dropped to 10% and the Class AB doubled it's output. In his Class A Threshold amps the provided 100% of their rated output in Class A into 8 Ohms, into 4 Ohms they provided 50% of their output in Class A as the balance of power output doubled into Class AB.
Again, though of a different design, Nelson Pass's Class A/AB Threshold amps provided the first 20% of out-put into 8 Ohms in Class A and the balance in Class AB, into 4 Ohms the Class A output dropped to 10% and the Class AB doubled it's output. In his Class A Threshold amps the provided 100% of their rated output in Class A into 8 Ohms, into 4 Ohms they provided 50% of their output in Class A as the balance of power output doubled into Class AB.