So on a whim I brought in the Gungnir and Mjolnir stack to see if I could free up some desk space without too much drop and... interesting results.
First things first. This was not a fair fight. $1600 v $7000 MSRP but this is Head-Fi so what the hell. Secondly the Schiit stack is awesome given it's price tag and maybe more importantly really synergize with each other, cancelling out each other's potential faults.
So if we assume the GS-X mk2 and PWD2 are neutral, humour me :P Then the Mjolnir is tilted up tonally and the Gungnir is tilted down. Ie the PWD2 and Mjolnir is a little too forward and illuminated and the Gungnir paired with the GS-X mk2 a little too laid back and dark.
But the Gungnir and Mjolnir really mesh well. Since both "stacks" played best as a unit what do I think you give up for opting to keep several thousands in the bank? Resolution and speed. The GS-X mk2/PWD2 combo does a better job of digging deep into the recording and almost slowing things down during busy passages where the Mjolnir/Gungnir combo is turning towards hard times. But it's the last 10% type difference, not a lopsided blowout.
So I can honestly now say my previous experience with the Mjolnir was in a large part the fault of the W4S DAC-2. But partnered with a warm dac it really is something else. Great dynamic swing and sense of air.
The Gungnir was also incredible and could bring life to a lot of the amps in the sub $1000 range that are often dried out and lacking down low. I would however avoid pairing it to overly warm sources or you could fall into dark territory. Headphone choice obviously plays a part here.
Should add. Kudos to Schiit for having the balls to crank class A bias to reasonable levels. Loves me some hot Schiit. The Mjolnir gets quite hot. Even the Gungnir is warm to the touch. Love it!
Always drove me nuts that Burson had a massive heatsink for a case and set the bias to levels that barely warm the case sigh.
Interesting observations. I love the Mjolnir/Gungnir, but feel like it still swings a bit bright. I was toying with the idea of an eventual GS-X Mk2 upgrade, but keeping the Gungnir, but it sounds like you think that pairing is too dark. The biggest reason for me upgrading would be getting a more neutral amp that plays well with lots of headphones.