I have been using the dolphin since last 2 years.
Every one says that dolphin has very bad network but comparatively it is not as bad as it is said.
But in terms of charges dolphin is the least expensive for call charges & SMS charges,
if you compared with other expensive service provider whose charges are almost double then
dolphin.Also the STD call rates are less in dolphin. Even the GPRS activation is also free of cost on
dolphin, where as others are charging so much on that.
Some time(rarely) it does give problem but that is the case with all the celluler services.
If you can compromise a bit I said a liittle bit & save lot of your money then u should always go for
dolphin.