I used idea service more then 6 months so I would say that coverage of idea is very good even in village areas also.
But this provider is very expensive then others. Network is very good and internet speed is almost same in every locations.
But where other network provider are serving on certain rate, idea is charging double of that.
For example in bsnl net voucher for 1 GB of internet pack is rs.155 there idea is charging almost 250 rs for same. And it also charge from ur main balances when pack is over without informing.
This is very bad experience of mine.