Is Purina: All Cats a good brand to be feeding my male cat?

Ceasar, my 2 year old cat has been eating cat Purina Cat chow ( the one in the blue bag; i think its for all cats) for, well all his life. but i wanna know if im actually getting my money's worth or if im feeding him just pure crap. my vet recommended Hill's Science Diet but its expensive for so little. i wouldn't usually worry about price but my mom HATES my cat and i don't think that shes going to by him anything too expensive. also, i hear that Purina leads to Kidney failure :| is that true? My cat has a long life ahead of him :)