I have bought a Karbonn KC441 only because I wanted to use my personal GSM number and official CDMA mobile without having to carry two handsets, but "KARBONN" was one wrong choice. FIRSTLY to begin with, the GSM calls get disconnected every 5-10 mins (issue resolved when CDMA SIM is removed) in short "THIS GREAT DUAL SIM CARD PHONE WORKS BEST WHEN INSERTED ONLY ONE SIM CARD). SECONDLY the sound quality and Network reception is really bad. One cannot use this phone when travelling in train/bus/rick/cab no ways impossible voice breaks all the way. THIRDLY Within the first 4 months the numbers and other prints on the body started eroding. FOURTHLY in the past 9 months, 3 hands free and 1 charger have managed to go on an indefinite strike causing me a damage of at least Rs. 250 everytime. simply speaking KARBONN is nothing but a CHINESE phone with some branding effort. Please think about buying this phone only if you are given one for free.