I have this system, and I also have "professional grade" systems. I bought this on fleabay for about the same price. Here's my take:
Pros:
1. Video is fluid, not jumpy, and records plenty of hours on a 500GB (it depends on quality/camera count/motion detect setting how long it will record)
2. Its small, and comes with evertying you need to set up, packed with features.
Cons:
1. Picture quality is garbage. Think your lawn is green? think again, probably will show up red. Invest in better cameras. Unless the cam is about 10 feet from the face of your subject. Don't plan on ID'ing that lawn-gnome theif with this. Also the IR is pretty weak, and shows up at night when somone looks at your camera as a big red circle... creepy really.
2. Interface, manual and network connectivity are not exactly the best (think "chingrish").
All in all, I'd buy this again for the price and check ebay for some used pro-qualtiy camers which can be had for about $10 a piece. Yay woot.