I would recommend that you actually listen to Diretta before making a decision.
I have had the opportunity to compare RAAT and Diretta on four different systems, including my own, and Diretta’s sound was by far superior.
RAAT is a superior transmission protocol compared to UPnP in general, but Diretta’s low load fluctuations during transmission are overwhelming.
Although there is a hypothesis that noise during transmission is suppressed, it seems that the stable transmission load suppresses power consumption fluctuations in downstream DAC-side electronics, which contributes to the improved sound quality.
