I would rank them as Hive > SMOS > Ethos from my experience.
The best thing about Hive is how quickly they keep new miners updated and bigger farm management is easier. I figured out in 1 hour with all the settings, there is no need to install patches for video cards with an upgraded BIOS.

SMOS is rock stable as well and if you are good with Linux, you can handle manual update of miners easily.

Using Hive OS, you can monitor your rigs from a single dashboard remotely and keep track of hashrates, GPU errors, pool configurations, power consumption, troubleshoot and reboot GPUs remotely, everything’s stable and they constantly add new features.