The DVRs they put in don't have much space.....seems to fill up fast......
Time Warner's whole house DVRs have 500 GB hard drives in them. Depending how much and what you record, you should have no problem not running out of space.
Whole House DVR for me has been a mixed bag. When the master DVR is recording, especially when both tuners are recording, slave units are extremely sluggish responding to FF/Rew commands and often craps out.
Most likely this is an issue with the processor power on the master unit, which simply doesn't do very well keeping up.