I got one of these last year for myself and another for my business. The DVR itself is pretty good. Software isn't always intuitive but is fairly solid and has good features, like fine grained control of motion sensing.
The cameras it comes with are very low quality and do NOT do sound. The DVR box itself supports sound as well as pan/tilt/zoom but you have to get different cameras. That deal sold 1/3" cmos chip cameras which aren't very sharp. They work well for basic security however.
The original deal I got advertised "weatherproof", but the specs (which at the time they did not make available before ordering) indicated a range of about 40-95 degrees. So apparently temperature doesn't count as "weather". They are completely useless in the winter outdoors here in iowa, and I suspect I will also have problems in the summer unless I shade them.
They sell a wide variety of other cameras, including pan, tilt, and PTZ capable for a wide range of prices. They also sell a few with heaters in them that can operate in the cold, but those are quite expensive.
I had to RMA three of my cameras - one was DOA and the other two wouldn't even get down to the stated low temperature point before starting to flip, but their RMA service was swift and fairly easy to use. One of them I paid for an upgrade exchange and am still waiting for the replacement to arrive. (was out of stock for several months)
Technical support is marginal on the average. The tech lines (phone and online) are frequently manned by salesmen that have NO technical skills, so you often have to call/chat at a specific time for real help. But when you DO get a tech, they provide fast, high quality support. The "24/7" chat is often not answered after hours.
The claimed ipod/iphone viewer support works, but if you want to view with a computer, you are confined to Windows, due to their requiring active-x. This was a nasty surprise for us here at work, with all macs in the building.
The brackets ours came with are cheap and are buggers to get the cameras positioned solidly. Even cranked down as hard as I dare for breaking the pot metal, they sometimes slip and have to be repositioned.
So the bottom line is, it's about a fair price for what you're getting.