That's a tempting deal on the Stellar GainCell! I'll have to read some reviews. I've had my eye on the Gustard A26, or maybe their R26 - I haven't decided which yet. I can buy it outright now, but I just bought the R8 about four months ago, my WiiM recently, and my DacMagic is only a little over 1.5 years old. Because of all that, my fiancé gave me a hard time about wanting a $1400+ DAC when ours sounds "just fine," so I'm trying to wait a little bit longer for things to cool down.

The Mofi deck is great. I've got a Hana ML on her, and WOW!
Yes, the mods I did are Skunkie mods, though I didn't do them all. I upgraded the important capacitors, split the front tube to feed each channel independently, upgraded the choke, and upgraded the resistors that feed signal to the biasing meter to much higher tolerance ones (0.1%). I've got a couple of resistors and mica capacitors on their way to me now so I can upgrade the GNFB.
I've upgraded all of the tubes, but since you mentioned Gold Lions, I put their KT77's in my R8, and they are really great!