it honestly depends on how much you use the service.
i had an account for a while to a site that shut down. while i had it i was downloading a bunch of different files, not necessarily pirated stuff.
i'd say if torrents isn't a viable option and you would be using that site downloading at least 500 mb worth of data a day, it might be worth it. if something you want is available only on one of these sites, it depends on how bad you want it and how soon you want it.