I can share some insight into the Lampizator dac as I am a reseller found at HDAudio.ca I will try and be as unbiased as possible.
There are 3 words that best describe their sound:
LIVE Natural Clarity.
The level 3 and 4 share the same overall personality. They both have the same basic DNA using an all tube power supply and output stage. The sonic difference lies mainly in the chipset used and it's voicing. The level 4 is basically about 10% better than the level 3 with a blacker background and better 3D imaging. 40% buy the level 3 and 60% the 4. Once people see how good the level 3 is 90% want to step up to the 4 and are happy. You can tell the difference between the two in one switching.
The first thing one notices is how live the sound is. Instead of a static, or lifeless, sound there is this expressive, lively, bloom emanating from the instruments. This makes it very engaging. Other things one notices are a great deal of detail retrieval, a sense of ease and flow as in real music, and excellent imaging.
Instead of a stark black background you get more of a clear one. Kind of like some Audio Research gear I have heard. Instruments and performers are spot lighted nicely. All of this adds up to going from great hifi to a real performance.
The sound is very addicting and has had me planted in my listening chair not wanting to turn off the tunes.
All in all, they are a very nice addition to the high end audio arena in my books.
Rocket_Ronny