If you want the 64 bit version you should first know what it does. If your running 32-bit software on 64bit version you won’t see any difference.
What are the advantages of 64bit? More bits get access to your memory. With a 32-bit processor you can only address 5 gigabyte of memory. With the newer 64-bit processor you can address upto 17.179.869.184
Will 64-bit run most of my apps ? Yes the 64-bit can run most of the 34-bit software but can’t support 34-bit hardware. Like the internet explorer utilities won’t work. This also means that all of your devices you need a native 64-bit driver, this maybe hard to do on older computers. Another great reason to pick the 64-bit version is because it does enhance your performance. It has been known to make your PC 10% faster. I would not be surprised to see a 64-bit OS only in the near future.