Compare both i3 and i5 processors:http://ark.intel.com/Compare.aspx?ids=43544,47663,
The i5 has TurboBoost, the i3 does not. So there's an advantage there.
As far as the ATI 5650 and 5470 are concerned. With a laptop your biggest bottleneck for any kind of gaming (I'm only assuming you want to game) is the GPU. Generally laptops entirely lack a dedicated GPU.
So personally, I'd rather have the i3 with the faster GPU than the i5 with the slower GPU.