Word of advice. Get a demo on a similar setup to what you decide on. Chances is that your expectations is going to be higher than what you get. Facial recognition is very important. If you can not ID a stranger, it is useless. To ID workers is easier, as you know them, but someone else, looking at the footage, might argue. Then, frames per second. If you want to see the exact action, make sure you get 20fps at least, not on paper, but in reality. IP based systems is notorious for lacking in these aspects. The specs is great, but the network can kill it.