RAAT was changed to TCP streaming in v234. To quote Mike from release notes on 234:"…we also know that both TCP and UDP, when implemented properly, are suitable for high-bandwidth, high-quality media streaming…". The complete text is here:
You are not guaranteed error free streaming with TCP either. Maybe if you tried the Bryston again now it would be more stable? In my own experience RoonAIR to my 250Pro is trouble free while Devialet’s AIR was unusable. So it is also possible with UDP!