The Redis SET command has some unusual features that set it apart from other commands, such as its ability to disregard the type of key and always write to it, whereas other commands will throw an error if the key already exists with a different type. This feature is useful but also potentially dangerous when not used correctly. The SET command also allows for optional arguments for expiration and existence checking, including NX and XX, which can be used to set default values or prevent accidental overwrites. Additionally, Redis understands loose typing of data types, allowing numbers to be treated as text and vice versa, which can lead to unexpected behavior if not carefully considered. Understanding these features is crucial for proper use of the SET command and its role in Redis patterns.