The fact that the decision has not been made between QSI and ESU is a positive thing to me. At least it is not the QSI default as on the F7s.
And it is not the sound that is the determinant to me, it is the motor control. If sound is a big deal then you should consider talking to the TCS folks. I think their sounds are the best and they are coming out with a 5 Amp decoder. So far their motor control seems on par with ESU to me.