sns, Thank you for your thoughts and in depth reviews as things evolve.
I have owned an 004 for 4 years and have had many other dacs and always keep the 004. It's a great DAC especially at it's price point. I've been looking for a used 005. I have found the I2S input out of my inexpensive Xingcore USB to I2S converter input by my windows Jriver PC to be superior to straight USB to the 004. I Will look into the Gaia but also seeking the 005. Is the 005 a worthwhile step up from the 004? Thanks again for your time and effort with the reviews.