Hi Philipwu,
Yes, the soundstage doesn't seem to be constricted anymore. I do not remember when it started but so far I've had about 4 weeks of consecutive playing time (amp off while not listening).
Octave, in my system, definitely is organic and forward sounding. I'm not sure the latter is an accurate description, but I meant it in a positive way. I guess it's like "you are there" experience.
The midrange is on par with Electrocompaniet ECD-1 dac. Maybe even better due to its organic nature. I have to dig in my memory for these comparisons, so bare with me when I cannot say one is definitely better than the other. Other than midrange, Octave is better than ECD-1 in other areas.
I want to say it is as detail sounding as Sabre32 dac (my experience is with Oppo-95 playing flac files off usb drive, Octave is currently fed by Synchro-mesh + AppleTV), but in a different way. Oppo is airier and has more delicate highs but Octave is forward and more real sounding. Oppo has slightly wider soundstage, Octave may be taller soundstage, if that makes any sense. On very complex passages, Oppo has more resolving power, Octave is detail enough to keep me happy.
For piano, violin, female vocals, my system sounds the best with Octave. This one I can say. Hands down, no contest. Octave midrange also smokes Oppo.
Octave bass lines are more defined but ECD-1/Oppo aren't that far behind.
So all in all, I'm happy with the purchase. I'm not experienced enough to say how much of a giant killer the Metrum Octave is, but I can say it's worth every penny and then some. By the way, I also tried Grover Hoffman powercord with Octave and heard better dynamics.
Next up is to try Yamamoto YDA-1, Eastern Electric DAC+ with Dexa opamp and Oppo-105 (due to come out in december, Modwright tube-mod also intrigues me). No idea how long it'll take but next year should be fun. :)
Components downstream:
Focal Electra 1008Be
Pass Labs XA30.5
Pass Labs XP-10
Nordost Heimdall XLR and RCA