Well i liked the look of them both and they are nice and slim so can carry them around. Also they are at the top end of my price bracket and have seen good reviews for both.
I've been looking for a camera to replace my aging Nikon 3.2mp and came to the conclusion the Casio Z70 was for me. I've been in and out of Dixons a fair few times because i never buy withoiut trying something first if it's possible.
Although i havent bought it as of yet [have other thing's that are needed more urgently!] i would definetely say to buy the z70