Set up was easy and quick. using 4 * 8tb drives into a raid 5 config.

A little slow to copy files too but it just for backup so speed is not a huge issue for me

If you need a good little storage unit that doesn't break the bank this is a great solution.

Been running problem free for nine months with 4 WD Red 4tb in raid 10 as one of my backups. Today I was reworking my media server (new raid card) and had the chance to try a shucked drive in this unit (shucked drives have that 3rd pin power problem causing them not to spin up with pc power supplies) To my surprise the White label WD 8tb drive fired right up and pretty much gave me full read and write speeds moving a few movies around as a test.

none so far

It will support a shucked WD white label 8tb drive, knowing this I may buy myself a second unit.

Decent RAID-5 speeds, low cost, quiet operation, stable

Finicky drive trays, no hardware encryption

After acquiring 4x 4TB Drives I needed something to pop them into. Running in RAID 5 (12TB array) with Bitlocker encryption I'm seeing sequential writes speeds of up to 185MB/s, with more typical mixed file workflows (folders of 20MB images for example) transferring around 80MB/s. I assume RAID 10 is faster, but I didn't bother testing as I needed the extra capacity. Build quality is about as good as could be expected for the price point with quiet operation, very little vibration (even with consumer barracuda's in it), and overall good build quality, with the exception of the finicky guide rails - you have to align the drive trays very carefully when inserting to prevent them from running over top of the metal guide rails. I was slightly off on one tray, which inserted far too easily in the wrong position, then caught on the sharp stamped edges, and jammed very badly when I tried to remove it - not a fun experience! Qnap's external raid manager software makes configuration easy, and provides SMART status for the enclosed drives - far superior to the proraid enclosures I've used in the past with nothing but a status LED to let you know what's going on (i'm staring at one right now with a little red x next to one drive as it copies over, and I have zero idea what's wrong with it) As a side note this has no hardware encryption support so I initially used Veracrypt, which as it turns out has a massive ongoing bug that absolutely cripples performance. Burst speeds unencrypted hit 220MB/s in RAID-5, Bitlocker manages 185MB/s, Veracrypt managed 40MB/s (all with no CPU use or overhead). Over the course of about a week I have copied about 18TB to the array (had to copy everything twice after my veracrypt fiasco) with zero other issues, so stability seems excellent. Wish it could be upgraded with an ssd for cache, but that's hardly realistic at the price point - if you're on a budget pick.