I agree if everything in your app follows a perfectly restful pattern, but what about if you want to capture application state that does not belong in a database. For example, what if you have an online store that has many different filters to narrow down selections. And you want to share this url with someone.

How would this be done using a RESTful url path? You have to use url params. If so, this seems to be a nice solution if your using a lot of params.