Canon A520 vs. A610

Hi,

I have a Canon A520 camera. I have used a Canon A75 before and I thought
that the A520 is an upgrade and the pictures would be better. It turns out
the A75 pictures are sharper than the A520 pictures. I changed the ISO
settings in the A520 and I am still getting grainy pictures.

So I am thinking of replacing the A520 with the new A610. I looked up the
customers' reviews on Amazon for the A610 and it seems like it is a good
camera. Do you think it is worth it to upgrade? Would I get grainy pictures
with the A610?

Thanks.