My thoughts on this are that it is best to use a standalone modem, and your owner router. My reasoning was formed when I was moving around a few years back to various apartments before I bought my house. Sold the house, back renting again for a little while, looking for a better place. With this, the router is ALWAYS ready to go for your network, if you have any special configs on there, such as non-default IP scheme, the wireless config, port forwarding, etc. etc. If you need to change services, router is yours, and still good to go, just get the new modem.
You might also save a couple bucks a month. From what I remember in the past, when they give you equipment like that, they typically charge you a few bucks a month to 'rent' it, since it is theirs, and you need to return it if you cancel your account.