Expectations and how they are met.
deliver the highest possible quality audio but sometimes there’s more possible but because of false self-advertisement of capabilities you won’t get it (Google Cast) or the manufacturer restricts input formats over network (only stereo on multi-channel receivers for example).
and even allow volume control right from the Roon user interface! should there be a volume control at all and the manufacturer made the volume control accessible through RAAT.
But no more than the available drivers allow, which depends on the OS and might not be what the device is capable of.
For the Bluesound 2i series and the KEF LS50W/LSX, the best user experience possible might be unusable. Also Devialet users might get consternated.
It’s hard for users to find out about possible restrictions even if they do research. The only way to get reliable information seems to be to research for other users experience as one will mostly not find these information on manufacturers product (selling) sites. The early-adopters seem to be the losers in this game.