I installed them end of last week - went well and had call from the customer this morning to say they are very pleased.
I put in the 4 cameras and in addition replaced the 250GB drive with a 750GB, which is quite a cheap upgrade really. Also bought the BNC to VGA adapter and 19" TFT.
The DVR pack is great and easy to set up. It is plug and play. There are two cables per camera (attached to each other) for power and video (BNC connector). Just run each one back to the DVR and use an adapter to plug the DVR into a TFT or use the included SCART for a TV if you wish. Use the on screen menu to set up recordings, i.e. which cameras to record from, brightness/colour settings per camera, quality setting, passwords etc. You then just need to install the software for a PC and connect up via USB (included but short cable - best to get a longer one (A-A USB not A-B btw)). As long as you're not recording, you can play back video and either capture still images or video and save to the PC. Nice and easy.
Its hard to comment on image quality as I'm not experienced enough, however the customer said it was much better than their previous system (some years old but looked like a more expensive solution than this) and were happy with night vision.
Overall a great system for the price. Might need to upgrade the odd camera if you want longer range or something but for general use they are great. The only thing that takes all the time is running and tacking the cables back. The set up of the system (which I did prior to install) only took 5 mins at most and some minor tweaks onsite.