Installed it on Saturday Feb. 18th.

Biggest discoveries after a couple of days to listen-

1) The quality of the sub bass is as good as I could ever want and matches exactly my preference for excellent subwoofer bass. It sounds so much deeper, tighter, fuller, more accurate and correct than my previous head unit (Pioneer DEH-P8300UB). I didn' change the amp, the gains, nothing. Just the headunit and one complete auto tune session with custom network.
I don't know where the credit should go but I have to believe the ultra steep cutoff slope at the crossover provided by the units processing (80Hz, 36db per octave) has really tightened it up immensely. This improvement leaves me unbelievably impressed. This head unit all at once made my subwoofer and amp that much better.

2) Just one auto EQ yields much better sound, stage, accuracy, centering, clarity etc. than the best tune I could achieve with several months owning my old head unit.

3) I ditched the auto time alignment. It seriously detracted from the sound. I will revisit some form of manual TA as time allows- but with former head units I never found it to be a plus.

4) Biggest so far- the clarity of the sound allows the volume to be turned up significantly louder without fatigue or harshness! Again, no change in amp or gain settings- the ultra clean signal this source unit puts out lets me really really crank the volume much more than my old head unit.
This tells me that a "good" head unit with decent specs is not all it is cracked up to be- and that specs do not tell the whole story. I thought my old deck was a decent sounding CD player and pre-amp, it had great SN specs, had a 24 bit DAC, etc. just that it didn't have audiophile features like parametric EQ, time alignment, etc. It had 5 channels, adjustable high and low pass filters, subwoofer level, etc.
The DEX 99-PRS literally blows the old head unit out of the water- it made my amp and speakers so much better and louder!
It is really unbelievable and a bonus that I was not expecting.