After a couple of weeks i can confirm that SDD is great.
I hate to use this word because it's just the every-youtube-demo-ever favorite word, but it's lush (

) : it sits there with your playing and reacts to it in a really dynamic and organic way such that it's hard to turn it off.
It's not an "aggressive" delay, i mean that even when at its extremes, it doesn't get into noise madness (which i like too), but i don't think it's what is supposed to do. It' a great, straight, warm delay with highly customizable tone and mix response. In some ways it reminds me of my other "set and forget" delay, the Boss DM-2W, but more tweakable and with better interaction with whatever sound you put into it, from aggressive fuzzes, to crystal clear twangs to big chuggy stuff and so on.
I usually just set the modulation to a sweet spot and then forget it, so I immediately set the left footswitch for infinite repeats, and I strongly suggest everyone to do the same: the infinite oscillations on the SDD are beyond gorgeous. The most surprising thing is that they seem to be perfectly dialed in in any possible setting, both tone-wise and volume-wise.
For the sake of doing it, i have compared those infinite repeats placing it in series with 2 other delays of the same category, with dedicated runaway footswitches, the PLBR Young Hearts and the Rubberneck. Just to be clear, i like them all, but there are some slight differences: Rubberneck is dirtier, grainier - if it makes any sense - and as a result of this when the oscillations kick in they seem to grow faster toward destruction. Young Hearts is more "neutral" in terms of tone, in fact that it doesn't have a tone knob, though the amount of control on the oscillations (attack, release, timebend, randomization) is really something else and incomparable to any pedal I know.
That's it for now, did i really need another PT2399 delay? absolutely no, but now i am super happy of having it.
