In my opinion, generally we can say that 64-bit system handles the big amount of physical memory (RAM ) more effectively than the 32-bit. The 64-bit system provides a larger space for your computing. Logically 64-bit system has the capabilities of utilizing a huge amount of RAM. But, Windows 7 can support up to 192 GB of physical memory, where the Windows 7 32-bit is only capable to use 3 GB RAM. That means if you install RAM more than 3 GB, it does not works in 32-bit system and the the rest of the RAM just goes wasted.In the case of 64-bit system, as it handles a huge amount of physical memory length, the time of swapping the processes in the RAM is minimized. Which means that your 64-bit Windows 7 performs faster than its 32-bit version.
Kernel Patch Protection is another feature of 64-bit version which adds a better security in Windows. It prevents the malicious programs from updating or patching the Windows 7 kernel. That means any third party tool can not modify the kernel services. This feature is not available in the 32-bit version of Windows 7. Where security is a mandatory requirement for the system, 64-bit version of Windows 7 is more preferable.