I have two 8 camera systems in my home, One is a Ebay unit with a 500gb hard drive, but i ended up replacing the cameras with Swan 700TV lines, The other unit is a Swan 1TB system with the same cameras.
The biggest difference was in the cameras the ebay ones were crap and failed after about two years, I don't have the systems hooked up the internet for remote viewing, as you need a secure IP address, And the wife was worried about some one getting the user name and password and viewing it.
It recently came in handy when we had the mother in law saying she was doing some thing but doing the opposite, needless to say she isn't welcome in my home anymore.