If you r using Iphone 4 in T-mobile in USA, could u pls give us your kind feedback here? The newcomers who r considering to jump out ATT highly appreciate your help!!
1. How do you feel about the internet speed under Edge (2G) comparing with 3G of ATT? How about using computer by tethering via Iphone 4 (such as downloading speed)?
2. Any inconvenience you find out using iphone 4 under T-mobile?
3. Do I have to jailbreak if we only switch to T-mobile? I know that Carrier Unlock is not available from ATT or Apple right now. Seems that other ways of unlock is based on the condition of Jailbreak, is that right?
4. A stable software for Jailbreak for IOS 4.2.1 is not available, right? Therefore, how shall I unlock or Jailbreak Iphone 4 updated to IOS 4.2.1?
I found two ways, but don't know whether it would work: (1) some advertisements on ebay or google show they could jailbreak IOS4.2.1. Is that reliable? (2) Some video show that I could downgrade 4.2.1 to previous version, then Jailbreak. I was wondering without any previous back up, can I downgrade it? Or I could download and use some other's back up?
5. In case I successfully downgrade it to the previous version, which software of jailbreak I shall use? Seems that Jailbreakme is very simple to use?
Thank you in advance!!