The Synology DS923+ is a strong NAS able to meet the needs of a small home office. The expansion capability, through an optional unit, is a strong advantage since it will allow you to add more disks if your storage needs increase in the future, and you won't have to replace the server with another larger one. I am not so fond of expansion units since they add complexity and increase electricity bills, but it is good to have that option. Another significant upgrade option is 10 GbE networking, though a PCIe card which costs 173 dollars (E10G22-T1-Mini). The pair of NVMe SSDs can also boost performance, especially in usage scenarios where high IOPs are required. Besides cache, the SSDs installed in the NVMe slots can also be used as storage pools, which is a great asset, given the increased capacity of NVMe drives nowadays. The only problem is that only Synology NVMe drives are supported at the moment, and these don't exceed 800 GB as we speak. Hopefully, Synology will allow drives from other vendors to be installed in the NVMe slots or/and increase the capacity of its own drives.

You might wonder why I didn't run storage tests using the NVMe pools. This was because I needed to have Synology NVMe SSDs in hand. Once Synology sends me some drives, I will run more tests. I need a whole month's work to evaluate a NAS server fully, so I am not so happy about adding even more, but I will make an exception in this case. You cannot operate this NAS with only NVMe drives because the operating system has to be installed on its SATA drives. So you have to have some SATA drives, too. I don't know if Synology will change this in the future, but it would be a nice upgrade. Removable drives/bays are a strong asset for any NAS, so I don't know why to get a 4-bay NAS if you plan only to use its NVMe drives. Installing the operating system on faster NVMe drives could offer lower boot times, but how often do you boot or restart a NAS? Moreover, in a failure case, swapping a disk from a bay is far easier than replacing the NVMe SSD. Lastly, the NVMe volume doesn't support hot-swapping. So before you replace or change any of the NVMe SSDs, you should shut down the NAS first.

The limited transcoding capabilities are another topic that I would like to spend some time talking about. Its predecessor, the DS920+ used an Intel processor with integrated graphics, which could handle 4K transcoding. Strangely enough, Synology picked the AMD Ryzen R1600 for the DS923+, which lacks an iGPU. They could have gone with the R1606G instead, which includes Vega 3 graphics, so that everyone would be happy. The TDP is the same as the processors mentioned above. Plex is supported, and if you don't have to do any conversions, the NAS won't have an issue, but if the client is weak and the server has to convert the media files, there will be issues. If you want a NAS for your home with a more media-oriented role, try to find a DS920+ or another NAS with a processor featuring integrated graphics.

In general, the DS923+ is a notable upgrade to the DS920+ when it comes to data transfers, which are the main dish for a NAS server. Besides higher transfer speeds, it also can utilize its NVMe drives as storage pools, and it comes with ECC memory, so your data won't be corrupted in the long run, and you can upgrade RAM up to 32 GB. The only downgrade is in the multimedia section, so I could state that the DS923+ focuses more on business applications where fast and reliable data transfers are the priority.