Nikon camera lens advice?

Hi
I'm looking at getting a nikon AF-S 18-70mm F3.5-4.5G ED DX AF Lens but i already have a Nikon AF-S DX 3, 5-5, 6/18-55 G VR Lens. Would there be much of an advantage getting if or should i look at a different lens? The 18-55 that i have at the moment i don't particularly like and we don't get on well at all. So what would be the pro's and con's of changing to the 18-70?

Going from an 18-55 to an 18-70 is kind of pointless unless your 18-55 breaks.