To answer the questions: Sound stage, yes it improved tremendously. And my unit still works without ever any hiccups or issues.
I find the 6922 tubes you put in the power source has a very significant impact. Tubes I've tried so far:
- JJ (stock tubes Mod Wright provides): too bright and a bit flat overall
- TAD: a little less bright and some holographicness going on
- Mullard: very smooth, but almost to the point where it sounds muffled, Over time this improves, but the holographicness is almost killed
- Amperex: Almost best sounding, most holographic but still a tad too bright for me
- Matsushita: favorite, has a bit of holo and the highs are tamed
Mind you my speakers and audio chain have their own specific need. Going to shop this morning a bit around for other premium NOS tubes...