I have heard several (apogee ensemble, mackie onyx, RME fireface, benchmark, and Pro Tools HD) and have never heard any significant difference. I have heard that universal audio used to make a 2 channel converter that sounds good, but only because of the analog circuitry in it. My question to my Moog brethren is do any of you have any experience with A/Bing different converters and can you recommend any exceptional ones? Also how important to your signal chain are the converters to you, because to me mics and preamps are the most important. BTW model D through Neve 1073 is butter.