Without paying you get PSIP information only. What you get with PSIP depends on what the individual stations send out for their channels. Most people report between 8-12 hours of information via PSIP. Some stations may not send out any real program information other than "to be announced". With cable it's cloudy. Most cable systems don't send any PSIP information because it has no use in their system and they are not obligated to do so. So it is unknown what kind, if any, guide information you will get without paying when hooked to cable.
Many, many unknowns that cannot be answered until real hardware is shipped and reviewed.