Summary: ..this is the hard drive installed as the OEM equipment in the Q-See QC448 security system (4-camera, 8-channel). This drive runs very quietly, which is good since it's in a fanless enclosure in the Q-See system.
Summary: 4 stars = I like it, so I'll tell you why. You need to know that I installed this in a computer I built to be fast and silent. It's a backup drive for a 240GB SSD and it gets backed up to a large external so 500GB is really enough in this situation.
Pros: Low power draw, low noise, runs cool, designed to handle multiple streams. Ideal for pre-Premiere Tivo HD models as it's not "advanced format" and doesn't have the head parking feature which causes older Tivos to freeze on warm boot.
Cons: Pricey for a 500GB drive. Western Digital makes/has made 1TB DVR-class drives at around the same price, but the models appropriate for pre-Premiere Tivos are hard to find.