We have purchased two of these so far to use primarily as NVRs for a large number of IP cameras on a school campus.Licensing costs aside, Synology Surveillance Station does a really nice job making it easy to set up and scale with the number of cameras you have. We linked two together, making one the primary and the other a secondary target for recordings.Surveillance Station records direct-to-disk, and does a decent job of adjusting camera settings directly using ONVIF.We have about 50+ cameras running at resolutions from 1280x720 up to 2560x1600, some PTZ, some ceiling-mount fisheyes, mostly wide angle fixed, and everything works pretty well. We were even able to use the manual camera configuration to use some uncommon double-lens cameras.With about 26 ... MoreWe have purchased two of these so far to use primarily as NVRs for a large number of IP cameras on a school campus.Licensing costs aside, Synology Surveillance Station does a really nice job making it easy to set up and scale with the number of cameras you have. We linked two together, making one the primary and the other a secondary target for recordings.Surveillance Station records direct-to-disk, and does a decent job of adjusting camera settings directly using ONVIF.We have about 50+ cameras running at resolutions from 1280x720 up to 2560x1600, some PTZ, some ceiling-mount fisheyes, mostly wide angle fixed, and everything works pretty well. We were even able to use the manual camera configuration to use some uncommon double-lens cameras.With about 26 cameras assigned to each RS422+, we see about 20-25% CPU on each on average during a typical day. We can comfortably handle 32 per unit, and supposedly up to 40 if needed. With x4 6TB drives in each set in SHR-1 (equivalent to RAID5) we have about a month or so of footage retention.The licensing is a little pricey at $50 per camera (unless you buy in bulk from some european IP camera shops...), but it is perpetual and I think worth the expense.Using two of these units, 8 cheap drives from eBay (luckily these do not suffer from the Synology whitelist) and a bunch of camera licenses, for around under $5000 I was able to build and set up a really easy to use and reliable NVR system with plenty of future expandability. 2-3 users are regularly connected on their desktops without issue.

I was looking for an efficient, short depth, 1u NAS, and that's exactly what this is. Idle power draw is low, it's reasonably quiet, and the Synology software was a breeze to work with. Super pleased with this purchase.