MTNL is good ! but what abt GPRS . Review on Dolphin Mobile Operator

Hi all my friends I am using mtnl dolphin from past 2 yrs ! its very good and out of mumbai it have good coverage coz its tie up with BSNL ! I m stays in mumbai I got some signal problems may be it will improve in future mtnl peoples always told me one reason ( NETWORK UPGRADATION KA KAAM CHAL RAHA HAI ) hope there upgradation will be completing in next 4 to 5 yrs hope fully ...... mtnl lauches GPRS but it have limited acess I m stays in navi mumbai I cant acess the GPRS when I call customer care and asked them they replied me its available only in between VT to MANKHURD and CHURCHGTE to BORIVILI and in EASTERN area VT to THANE after thane its not available till kalyan ! how funny this is they peoples STARTS the GPRS but in limited areas ! baki jagah UPGRADATION CHAL RAHA HAI SHAYAD ,,,,,,, hey friends if anybody have information when they starts in navi mumbai pls reply .....