I appreciate the hard looks at this. It may be because I have a very efficient set of cabs, but I rarely need to turn the amp up very high. Playing outside I have never gotten much past the "6" and in my garage, no matter how loud my son plays I don't need much above 2 on the master. I don't usually use the drive knob on the amp because I prefer the drive from the SansAmp BDDI.
I don't really hear compression with the tube in. I am not great at reading schematics, but it looks to me like it comes in after the solid state compressor. But I think I at least have a better understanding as to why the consensus seems to be that tube in/out makes little to no difference in sound. I actually stopped using my compressor in a stomp box because the compressor on the amp seems to sound pretty good.