Sure! I was hoping you wouldn't take that wrong and become angry. Good. My understanding of it in a nutshell:

If a signal chain is generating a noise output that is fixed verses signal output then a sensitive speaker will cause the noise to be more audible. For instance a set of 106 db/w speakers would make the noise 16db louder than a 90 db/w pair since the listener adjusts the signal volume to be equal with the preamp volume knob.

Thus the effective noise floor is raised.

The 'new' 950 raises and lowers the 'hiss' with the volume. The old one did not, although the (non-variable) noise was low enough not to be an issue for most.