Some of my remarks as for comparison OCTAVE with ENVY-
Octave v16 without black box;
I did not mess with driver tubes, EF800 is virtually impossible to change, ECC82 is not easy to replace since it is put deep intro amp chassis. I have a lot of 12au7 for Riviera and I will try to roll it- in Riviera results are far beyond any expectations. As for power tubes I started with standard TungsolKT120 with average result, so I switched to KT150- much more satisfying. Now I USE Svetlana winged c KT88 that I do like and Valvo EL34- both charming , typically tubey sound with a lot of power and detail, good 3D presentation.
I do not consider ENVY or Octave better from one another, but rather use it depending on my mood for specifis music presentation, both amps are excellent.
Most important feature in V16 sound is imho its powerful yet detailed and highly musical presentation, authority that people describe often as iron fist in velvet glove. ENVY is for me second in this respect, but by small margin. I would attribute this Octave advantage to The very nature of tubes used, especially KT88.
Both amps have similar extension in high frequency, Octave goes lower in bass. This is very much dependent of power tubes used too.
Octave with softly sounding EL34 has much more tubey character than any other amp except for Ayon HA3-unbeatable in this respect.
Best dynamics-Octave with KT150, but you loose some thrilling delicacy.
tube rolling- unlimited , I DID not experiment with 6SN7, no need for it now imho, but I will try in future definitely
Noice floor- very very lowlevel in both, Octave better by small margin, and I do listen loud.
I do not have clear preferences of music genres between amps, although for EM, rock and roll, blues I use Octave more often, for jazz and classical- ENVY
headphones used- ABYSS TC1266 most of The time, Focal Utopia classic model, ZMF Verite closed and open, Meze Empyrean.
Susvara in future , maybe something else too
THESE ARE OF COURSE MY SUBJECTIVE FEELINGS AND OPINIONS
Summing up- I would not get rid of Octave, which has a lot of sonic advantages and nothing important to worry about.
And I defitely recommend ENVY