Just came across this thread, and can def give an opinion, for what it's worth.
I purchased a used Little Dot 1+ from a forum member here (board rev 2.0), for $75 shipped. When I received it, I sourced a couple cheap PhillipsECG 408A tubes which are the same design (minus the gold pins) of the 'famous' Sylvania GB408As. I also swapped the Opamp for a BB OPA2107, and also tried the LT1364. Total cost for everything was $42, bringing my total to ~$120
I have a few cans: HD650, HD600, Phillips X2, HE-400i, Grado 325e, Custom Magnum v5 Grados in wood enclosures, V-Moda M100, Beyerdynamic T51i. With every set of 'phones, the sound was fantastic, and volume was never an issue with any of these. Noise floor was black as night, and there was zero hum. I used a Bifrost Uber/USB and Aune T1 MK2 with custom tube and cap repalcements for testing. Microphonics were also very good to non-existent.
I recently picked up WA6 and a WA2 that I found on my local classifieds, both of which had been modified with expensive NOS tubes, and came with a stack of extra tubes for each. I love the look of the Woo gear and was looking for a piece of living room 'statement' equipment, one for high impedance cans, and one for low impedance. I bought both amps from the same fellow, and got a great deal - but total cost was around $1500, each piece being about 6x more expensive than the LD1+.
Here's the rub: I didn't like the sound of the Woo Gear. At all. The noise floors were higher, there was a slight hum on the WA6, and the WA2 was underpowered for most of my cans (though not surprisingly). The WA2 sounded more lush and warm, while the WA6 was a bit brighter and more towards neutral. After many hours A/B/Cing, I came the conclusion that I was looking for a sound that was essentially somewhere right between what they offered - which is exactly what the LD1+ has. A warm not-quite-lush tube sound that is simultaneously somewhat neutral with a hint of brightness, though never harsh.
I know we're not comparing apples to apples, but it blew my mind that both of these high-end-ish amps seemed subjectively AND objectively worse than the 1+.
Something else occurred to me after more listening. The sound of the 1+ is very close to another amp I have - the Lyr 2. I have some Aperex 6922s and La Radiotechnique ECC88s for the Lyr that sound fantastic. Unbelievably so. They better - they cost about half what the amp did. But what really gave me a wow moment - while A/Bing the Lyr 2 and 1+ using my Schiit SYS - was how similar the sound is. I'm not really an audiophile, I just know what I like. And I like the sound of these two amps. Sure, there's just plain MORE with the Lyr 2, but it's not night and day.
I would go so far as to say that with low impedance cans, one could comfortably get away with a Schiit Modi 2 Uber and Little Dot 1+ all day long, and be happy for a very, very long time. I know I am