ok let me think of a provider i will switch tooo
BSNL - worst provider.. forget it ..
AIRCEL - u may never know when will the problem will start with this network..
VODAFONE - little coverage.. worthless
AIRTEL - little costly but wait.. just few weeks ago airtel raised my validity to 3 more years for free stating that i am a priveleged customer ( using airtel for more than 4-5 years )
so i dont think i may change...
anyway nice option for many to switch to better network without fearing loosing the nukmber