I'm still running my gen8 microserver - it was <200 GBP when I bought it something like 9 years ago, and I still haven't found anything worth replacing it with.
With modern HDDs I can however saturate the SATA controller, whilst it has 2x SATA 3 and 2x SATA 2, I can only achieve ~5-6 Gbps cumulative, not the 18Gbps you would expect. It's certainly not a disaster, but does mean writes especially are slower than expected (2x write amplification).
At some point though, SSDs will beat hard drives on total price (including electricity). I’d like a small and efficient ECC option for then.