Service is determined by your sim. Changing the imei would do nothing other than circumvent a trace from a stolen phone, which is why most providers require it.
ofcourse you can use a low cost mobile which can do the trick. Yes you will miss browsing etc etc in SGS2 but changing IMEI is illegal and punishable by law. Guess you are better off with any cheap mobile
Changing IMEI as said is illegal in many country s and a big negative is that the phone uses IMEI to connect as part of its handshake process .
Therefore should not really be discussed on XDA and may lead to a blocked phone at a later date .
Service is determined by your sim. Changing the imei would do nothing other than circumvent a trace from a stolen phone, which is why most providers require it.
Not always. My AT&T plan will only allow data on my HTC Aria. If I take out my SIM and put it in my SGS2 I get poorer quality voice and no data service. Something in their system ties my SIM to my phone and my plan.