Have been testing this for the last few days and it really does what it says on the tin-whatever you put through it simply sounds better! I have many exciters and "vintage" EQs and none of them could open up a mix-or single track/group-as well as Pi & Phi. It feels like you can reach inside the sound and the controls are very forgiving too so it's hard to make it sound bad.
Obviously if you add a lot of mid-and-top enhancement then the low end is going to sound less deep in a loudness-matched setup. Apparently this is going to be addressed in a future update, but until then it works great to use their equally-new Musiqual Red, Blue and Green EQs to add low-end weight and make the sound even more expensive. To me these don't behave like regular EQs, but more like analogue colour or tone boxes with added sound-shaping capabilities.
There is no manual and very little other info but when you put Pi & Phi(and the other 3) into a sweetening chain and then take them off(with loudness matching of course), it feels like you've just gone back to making demos instead of records. The plug-ins "envelop" the sound with an open, satisfying, 3D, big-studio quality that is hard to "un-hear". Thumbs up.