Sorry but had quite the opposite experience even with the professional lines. The only NAS i trust is a Server (at least HP mini server) and ZFS. Stuff like unraid is for Windows mindsets, i don't trust HW-Raid and i especially don't trust Closedsource Software BS for stuff like that, exceptions are Enterprise stuff like EVA's or NetApp and EMC.
They where all from that RS -Series i think we had about 15 of them from RS14XX to RS1219 and all of them destroyed their own Raid after around 2 years just like that, no firmware update before that or other things that could trigger such a crash.
Sorry but had quite the opposite experience even with the professional lines. The only NAS i trust is a Server (at least HP mini server) and ZFS. Stuff like unraid is for Windows mindsets, i don't trust HW-Raid and i especially don't trust Closedsource Software BS for stuff like that, exceptions are Enterprise stuff like EVA's or NetApp and EMC.