When copying files between local and remote, frequently copy files that already exist. This brings up prompt to "Overwrite?", where options are y/n, or y/n to all. Would be nice to have additional option for some kind of file rename. Cyberduck has this, believe the option is to rename existing file (that's probably preferable to renaming the file being copied, but always nice to have options). When I'm manually saving files (outside WinSCP) to avoid overwrites, I append a timestamp, but that's just me.