iPhone 5 T-Mobile Speed Test HD

Just purchased an AT&T version iPhone 5 and unlocked it for my T-Mobile service. Looks like I am getting good download speeds, and the icon still reads "3G". I am usually getting the 3G icon most of the time and good data speed in the greater Sacramento area, but occasionally goes back to 2G/Edge. Settings: MMS APN: epc.tmobile.com MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc MMS Proxy: 216.155.165.50:8080 MMS Max Message Size: 1048546 MMS UA Prof URL: http://www.apple.com/mms/uaprof.rdf