I think it's very important to have a "speaking" URL. That is: I do not recommend to store a serialized, non-human-readable state in the URL. This could lead to the impression that the link can safely be shared because it is not visible what kind of offensive information the state may contain (such as some sensitive search query history).

Having the state stored in speaking URLs in a transparent manner allows advanced users to easily strip information they don't want to share.