I have run 32 bit TC for years (decades?) now, and have been too lazy to switch to its x64 counterpart. Mainly due to the facts that "it works" and that years (decades?) ago many plugins weren't yet ported to x64. This has certainly changed over time, but given 32 bit TC still works Ok, I haven't felt the pressure to migrate.
Apart from the fact x64 could can edit, compare and work with much larger files (which actually will never happen in my case: I seldom deal with multi-terabyte-sized files at all), some differences I have noticed are:
- System-context menus: Files and folders context menus differ greatly across versions and some menu items are xidden inside a "x64" submenu in TC-32
- Drag and drop: Some drag and drop operations between TC-32 and native x64 apps behave differently or aren't allowed.