I don't know what all it updated but I do know one large improvement.
I had a lot of problem with the data service with this phone. Small attachments in email and MMS and downloads would take FOREVER to finish. One time it took an hour to download a 1mb app. Web browsing was painfu, I would have to turn off and on 3G data to get it to respond. Verizon network is the best in the area and thats why I bought this phone. I could be sitting with 5 bars of 3G service, and the uplink would be blinking every 5 seconds with no response from the downlink. And do you think Straight Talk had an answer??? And I can barely find an answer online.
Can you feel my pain!?
I've been using the phone since the update and it doesn't hesitate anymore. Speed test showed 1503kbps down and 876kbps up. Before this update, on a good day I might have got 200kbps down, unless it stopped responding.