I can send and receive MMS and text messages. Group messaging works fine also.
Couple of notes:
Cellular network must be set to 2G in order to send text messages
MMS settings were manually inputted in cellular settings: APN: fast.t-mobile.com MMSC (URL):
http://mms.msg.end.t-mobile.com/mms/wapenc MMSC port: 80 (this popped up automatically for me) Maximum MMS size: 100 (note: originally I set the size to 1, but the photos were super small when sending)
Also, in messaging settings, make sure to click on "MMS delivery confirmation". Without this checked on, sometimes MMS messages show up blank to recipients