Comparing the Stealth to my LCD4 and I can confirm a few things. If the LCD4 sounds better than the Stealth, it's because of the distortions in the chain, (USB chain, transport, power quality). After modding my IFI Diablo with external power, the Stealth exceeded the LCD4 by a lot in all counts. The Stealth is a revolutionary leap and I want to thank and congratulate Dan Clark and his team for the breakthrough technologies he incorporated in this HP.
The same behavior is seen on the Dave. LCD4 sounds great on USB input while Stealth sounds grey, undynamic and even distorted. Even more so on redbook that I've lost interest in listening. When I got the SRC DX, it opened up the floodgates on the full potential of the Dave. Stealth sounded full, smooth, pure, linear and with zero resonance. Going back to the LCD4, it sounded shouty and the ear pad resonance starts to show itself too much.
With the Diablo and the Dave, I can hear the room in the recording on the Stealth. With the LCD 4, I hear too much of the earpad (or the environment within the seal) that it creates its own room and overwhelms the ability to hear the room in the recording.
The Diablo pairing is amazing too with MQA and balanced. MQA is also the best format for the Dave to my surprise. Diablo + Stealth 4.4 is the only time I've appreciated balanced. There is a track i use where I'm studying the detail of an instrument and it's biased to the right a bit on Diablo and Dave 6.3mm. With 4.4, it's smack in the center. I use low gain on the Diablo for both 6.3 and 4.4 as it is more resolving.
Stealth is perfection in my book and easy to drive. I am a big convert. Don't wait for an open version as this faithfully captures the room in the recording with zero resonance from the can. I've had chains where it WILL sound undynamic and disappointing as many other impressions here and canjam have claimed and I can confirm that it will be the sound you will get if the chain isn't optimized. Don't waste the potential of the Stealth by using a beefy amp as it's boosted color will ruin all the true resolution of the track that the Stealth has the ability to give.