Bowlers say that it as a more pronounced seam, which helps create early reverse swing and spin / bounce on lifeless tracks. That's why they want to continue with SG. I say that it's time we start using the Kookaburra balls on a regular basis. This will force bowlers either to develop the ability to bowl fast (as opposed to the countless trundlers we seem to have presently e.g. Praveen Kumar, Irfan Pathan) or start to really spin the ball (as opposed to lob it up as does Amit Mishra).