K, From your response it appears that one of the ways they made it run cooler was to roll off a bit of low end. It makes sense in a way, less low end, less work, cooler amp?
The good/bad news is that the tone has changed a bit. They seem to have adjusted the hi pass just a touch for a tighter, punchier tone down low (which is a good thing in the mix, even if it doesn't have that huge, fat, tubey low end like the original Powersoft module loaded 500's), and the upper mid response is warmer and has more character... so a bit louder and punchier and tighter.
