If you double that $1500, then the Musetec 005 is the much better DAC over the Gustard X26 Pro. I sold my Gustard to buy the Musetec. However, I wish I did not since I later had a need for a warm DAC with details.
I helped setup a listening station with 3 RME ADI-2 DACs. It sounded OK but I preferred the warmer Gustard X26 Pro and definitely preferred the Musetec 005.