64-bit systems can run 32-bit applications just perfectly. So question arises, is there any difference between using a 32-bit and a 64-bit version of the same application, IF the application does not consume a lot of memory.

So is there difference in performance as well? In any way??

If there is performance difference then I have to pack both a 32-bit and a 64-bit version into an installer otherwise I can just give every windows system a 32-bit since all windows can run 32-bit.