I own two other DACs purchased when I switched from the EAR Acute (2005), the COS Engineering D1v ($9000) and D2v ($5000) retail. They are gorgeous units which even my cable/equipment manufacturing friend says are also exceptionally built. However, they have a 1 second delay algorithm which blurs and expands the sound and a bypass which is relatively dry sounding.
The D1 is like the Benchmark L4 to a great extent. It is so clean and clear in bypass mode with wide frequency response, wide soundstage, dynamic. BUT-it lacks 3-D quality (minimal depth) and has a sort of sterile sound (missing body but great tonal quality). This is what it also sounded like on 3 other systems and none of my friends liked it compared to the D2v which has only a single linear power supply, single transformer, etc. compared to the beautiful D1v. It has a warm, lush sound like a CJ pre-amp. It has more limited bass and rolled off highs, less open but oh so sweet for voices and acoustic instruments. I intend to sell both now as I bought the super modified Benchmark HDR1 DAC which obliterates those two DACs and sounds like 5 figure DACs like my friend’s Ultradac ($23K), maybe better. Cost-$800 for a clean used unit and $800 in parts and labor.
P.S. I tried a dozen different transports on the COS units. The Benchmark sounded better on the three I kept by a mile. The COS units had the same sound profile on ever transport, the Benchmark shows the significant differences.