What are the benefits and constraints of using Term References Vs List (text) for product attributes?

The reason I ask is because I have some very rarely used attributes which I don't believe warrant their own Taxonomy, but I don't want to create any constraints within the system by using a List (text) field opposed to Term Reference.

For testing, I have created two identical example product variations and products, however the attributes on one are implemented using Term Reference, and List (text) on the other. Apart from the standard functionality Taxonomy provides for Drupal; is there anything extra that it is utilized in Drupal Commerce (categories is an obvious one)?

Thanks