Thanks for posting the updates, Bunky! Here are some more:
319: united.com shows N838UA has WiFiStream
320: united.com shows N403UA, N408UA, N412UA, N413UA, N421UA, N423UA, N452UA, N453UA, N455UA, N459UA, N460UA, N478UA and N485UA have WiFiStream
No 744 updates at this time