Reasons why you must steer clear of earth roam
1) you will always be charged more than published call rates.
2) very poor sound quality.
3) frequent call drops (charged per minute )
4) balance expires in 6 months but they wont tell you that when you buy the sim card,
5) no response from customer care.
6) do not fall for the gimmick of free incoming calls in so many countries. Remember this sim card has a uk premium number. All calls made from india are to a uk premium number and the standard call rates to uk do not apply.
It is much better to buy a local sim card at the country you are visiting. Sim cards are very cheap in almost all countries and you get transparent and much lower call and data rates