I had Musician Pegasus and of course when I wanted to upgrade one of the DACs I considered was Musician Aquarius.
The funny thing about Aquarius, yes, soundstage was better, separation was better, everything sounded more coherent but it did not feel as musical as Pegasus. To my ears the sound was brighter but somehow didn't encourage toe-tapping like Aquarius. I guess it sounded more uh....analytical?
Anyway I tried many other R2R DACs, including the top-end XLR Rockna Wavedream and a few upsampling D/S DACs for good measures. And I settled on Lab12 Dac1 Reference. It's slightly cheaper than Aquarius and very barebone in features in that only accepts signal to 192 Khz, but the sound is glorious. Seriously, to my ears, it sounded better than Wavedream. It is certainly a good candidate for end-game DAC. If you have a local dealer you really should give this an audition. One other DAC that really impressed me at this price range was TEAC UD-701N, organic and non-fatiguing as well. You might want to consider that if you wanted a more complete package of streamer and pre-amp.