I owned both a Brooklyn DAC+ for a year and a Liberty for 6 months both now gone and replaced with a Yggdrasil A2. The LPS most recommended for either Myteks is the Uptone JS-2 though you can get by with an Sbooster. The USB implementation on both Mytek DACs is not great and you gain significant improvement in SQ from just using a $179 Schiit Eitr USB to S/PDIF converter. Never heard the Stello U3 but it is well regarded. It is an older design though. You don't need a certified MQA DAC to listen to MQA files at higher than 44 on Tidal. The Audirvana+ player does the first unfold to 24/96, costs $75 and there is a 15 day free trial. MQA is hit or miss on Tidal anyway. I have both Tidal and Quobuz and SQ is better streaming on Quobuz. If you have to have full MQA I think going for the Liberty/Sbooster/Eitr is the smart move for most if you don't have the DIY skills to use the Astron. As far as the Brooklyn DAC+ compared to the Yggy A2 SQ there is no contest. I would rather listen to 44 through the Yggy than MQA using the DAC+.