A real SPG is a simple and mechanic device, just shows pressure and does not need a battery. In a stressfull situation one glance at the digi2 would just confuse me. It's neither a TC or Bottomtimer, because there is no actual "timer" funktion, nor a SPG and does not even offer light, when already battery operated.
Dont get me wrong to everyone his own. If you with your million dives are happy with it why not. I personaly find it neither fish nor meat and an addtional failurepoint (battery) But I give you that it looks cool and I also tried to sell it to myself, but jsut could not because of the points up there. Anyway enjoy it and safe dives! ;-)