They're pretty good in the daytime. At night, pretty grainy. If you need to identify something at night, forget it, use a 4MP with a bigger sensor instead. The best part of the 2499 is that the turret is just a little smaller than the Hik's, and so they are easier to get into tight places. Built-in audio as well.
Amcrest sells these and you can "sideload" Dahua firmware on it. Or forget all that, order these from Andy, and enjoy.