I recently got one of those passive boxes with an N5105 for opnsense. But I found it ran pretty hot. I was able to replace the thermal paste and shim the cooler a bit to get it closer to the CPU (there was originally a huge gap they bridged with a glob of paste), and it lowered the temps a bit, but it still hung out around 60-65c afterward. I think that could be OK, but it still just felt too warm too the touch. I ended up placing a USB 5V fan on the outside of the case and now it sits around 40-45c which I'm more happy with. But now I have a fan running 24/7 running on my passive device.

At the end of this ordeal, I bought another machine (MSI Cubi-N with an N200) for cheaper than the Topton Aliexpress job, which includes an internal fan. The fan is super quiet and the build quality is way better. And it comes from a reputable manufacturer which I trust more to not load any weird stuff into the bootloader. If I could do it again, I'd probably try to make my Opnsense router out of an MSI Cubi N with an N100 or N200, in both cases it would have been cheaper, more powerful, and use less electricity than the Aliexpress passive one. The only possible hiccup would be non-Intel nics that the Cubi comes with.

Just some perspective from someone who recently bought a couple of these devices.

These machines are super attractive spec-wise for their cost! However, and maybe it's FUD, I don't really trust the power supplies or the firmwares on these units. I'd much rather pay for a system with a power supply that is UL certified and a system that, at least on the surface, has a much better chain-of-custody for processor firmware. I know I could replace the power supply with something UL certified, but that now means I'm contributing to e-waste needlessly. My eyes are currently peeled for a 12th-13th gen i5/i7 1L system in my price bracket, as between the heterogeneous cores to get solid power efficiency, the ability to drop 2x NVMe SSDs and a lot of RAM, and on some of them, even the ability to get 10 Gbit, I can hit my ideal performance per watt budget and take advantage of my NAS for high performance decentralized storage.

Can't disagree with you there.

And I'm not a huge fan of the form-factor either, it gets messy once you've got your SATA connectors, power and ethernet.

Not suggesting Zima is the right solution, but ebaying dated hardware often isn't either for many of us.

Don't get me wrong, it's great there are people who can use this stuff and not pay disproportionate prices for electricity to run it; but much of the world isn't in that situation; maybe one day.

And 2X SATA ports, although they may not have enough power to drive 2X 3.5” hard drives.

You could do 2X 4TB SSD ZFS RAID1.