That’s right.

I’ve run a TR-004 for the last 5 years haven’t had any reliability issues so far. In hardware raid modes, drives are hot swappable but you can’t grow the array without wiping it. I’m JBOD mode you need to power off before swapping drives. The main problem I’ve had is their chipset is only partially supported by smartmontools due to proprietary crap so there is some strange behaviour there.