Here's my view on Yggdrasil vs Master 7
Schiit's digital filter is so much better than audio-gd's implementation. Yggy has very accurate/real sounding soundstage with depth. Master 7 sounds wider but is very flat in depth. Yggy has more stereo cues and spacial information. You need to use speakers inorder to hear the Ygg 3D soundstage.
Yggy has much more resolution/microdetail than Master 7. Master 7 is no slouch either, but ygg outclassed it.
Tonally Master 7 is more lush/veiled and darker. Yggy is brighter and can sound glassy. Both offer the same kind of natural r2r tone in their own way.
Yggy is more dynamic/explosive, Master 7 is more reserved/relaxed.
Yggy is brutally honest on bad music, Master 7 is more forgiving.
Master 7 is slower on attack and has much longer decay on the sound envelope, Yggy has faster attack, but no additional decay.
Master 7 has boomy bass, Yggy bass extends deeper and is stronger.
Master 7 requires I2S ddc to sound best. Yggy can get away with it's gen3 usb.
Master 7 runs hotter than Yggy and is quite heavier.
Yggy has annoying relay clicking noise and delay+muting when changing sample rates. Master 7 dsp does sliently and on the fly.
Master 7 is more tweakable and more DIY/Repair friendly while Yggy is quite a fortress/complex electronic.
Acoustic Guitar is where Master 7 sounds best, while Yggy really excels in presenting piano.