I have the DS920, and it seems to be getting a little old at this point.
If your NAS is showing it's age for hosting applications, consider hosting applications that are not working well on a low power mini PC. Lots of people host Channels DVR on N100 based mini PCs running Windows or Linux. They draw very low power and do a nice job at serving up Channels DVR. With the Intel processor, transcoding works natively off of the iGPU placing very little demand on the CPU. The N150 CPU is very new and the future yet there are still some support issues for this new technology. If you need more CPU than the N100 can provide, choose something a bit more powerful.
I have Channels on a DS718+ and it's still running fine, but over the years playback in the web UI has gotten slower and slower to begin, to the point of being unusable. Apparently that's because of the transcoding required, which would also affect remote streaming if I used that feature.
I'm still happy with my Synology because it's low-maintenance and I only use it with my Fire TV clients at home, but when someone asked about choosing between an M1 Mac Mini and a Synology NAS, Channels developer @eric confirmed this is a known limitation:
The M1 Mac Mini is 4-5 years old now, is it still recommended? I do have a Mini PC with a Ryzen 9 and 32GB of ram, but that just seems like complete overkill.
Eric recommended the M1 MM only three months ago, so I'm guessing the answer is still yes.
Yep, the M1 Mac Mini is still a great machine. It's still my current DVR and I haven't run into anything where it hasn't been more than powerful enough.