I'd love better import and duplicate detection features. I might even wait to see what comes of this before I import the bulk of my library. I've already invested my Google Photos and my phone but the majority of that can be replaced by higher quality photos in my iPhoto library.
I bought a used QNAP TR-004. Seems to do the job but I didn't realise it doesn't support migration or expansion which is a bummer. Expansion in particular, I bought 3 8tb drives so got an empty bay that will be awkward to fill when needed.
Yeah I've got a t480. Sweet spot between upgradeable, repairable, affordable, performant. I've got a secondary NVME in mine for Debian. It's got an internal and external battery. I replaced the thermal paste and the internal battery in about 20 mins. Very pleased with mine.
And keeps the playback time updated on local files. It also manages surround downmix better than the internal app.