As commented before: 30% faster single-thread, PCI-E and higher RAM capabilities... BUT... 30% slower multi-thread HW transcoding completely removed No included upgrade to 2.5 Gbps ports or higher (R1600 natively supports two 10 Gbps ports, so they purposefully removed them) Synology messed this one up BAD. Second hand DS920+ and DS918+ prices are starting to go up. What a mess...

When I hoped to get a used DS920+ for a bargain... Synology launched the DS923+ and prices went up. What the hell... However, a 10 GB NAS is a wonderful piece of technology.