I've been using the Helios 4 for a while now, no significant problems (can't help the post above... not my area!) - hopefully others are getting good use from it?
Sure, there's no power switch (it's intended as a 24/7 device - they may add one in future) but it's pretty quiet for a home office. I had NO problem assembling it (using HDDs spinning drives, can also work with SSDs). Powers down the drives when not in use, therefore not much power use for casual users.
Very easy to set up OMV on the SD card (use a good quality one) and it has the plugin so as not to wear down the SD preinstalled... booted and configured first time with the serial cable (provided) connected to a laptop. Once configured, easy to admin from a web interface across the LAN.
Also works OK with Windows machines on the LAN... configure it according to the manual (or the Techno Dad Life videos on YT)... not too hard, even for a non-pro like me. Moving slowly over to Linux for personal computing anyway!
I'm not yet fully across the use of Dockers and plugins etc but that's on the to-do list... as is better use of backup & sync utilities & cloud sync (encrypted TNO, where possible, of course).
I hope there is a batch 4 soon... may get another one! Don't forget, ARM based, with ECC RAM and 4 Sata ports... operates headless, not a bad unit.