Firstly this is a low cost airline. so one should not expect the same things one expects from jet airways, etc. so u have to be careful while booking tickets becos generally such ticktes are non refundable, non transferable, non rerouratable, etc. U want a low cost airline and then u want to have the benefit of changing ur schedule at your whims and fancies as well. that is practically not possible else such airlines would have to shut down.
They make money precisely on people cancelling tickets or rescheduling their plans. so far as service is concerned, they are punctual, very polite and courteous, the leg room in between the seats is very nice. in fact I was pleasantly surprised with the leg room and it beats jet airways hollow on that front where u feel extremely cramped for space. Go air is quite spacious in the leg room front. apart from that the plane is generally well maintained and clean and the ambience is good. thumbs up for me surely.