1 megapixel cameras has HD ready resolution. Most of cameras has 1280x720 pixels resolution. This is not big resolution, but this system has advantage too - this cameras takes not so big space in recorders, so you don't have to buy big hard disks to have good archive space.
Price of this cameras is very good, you can buy camera from 30 Euro. So it is good cheap system for home usage or for small business. For 1 megapixel cameras you can buy number 4 series HDCVR video recorder, it is cheaper, but has the same functionality as series 5 HDCVR.