What do you really need?
Reviewed in the United States on 1 April 2021
I really went back and forth when purchasing this unit. By the way, I haven't received it yet. But...I have been using a DS216J for quite a few years now, maybe 8 yrs, possibly even 10 yrs.
So, this unit, the DS220j was about $170, and the DS218+ was $299. The DS220j has fixed memory and it can't be expanded while the plus series and the DS218play can have the memory expanded. It really bothers me that Synology doesn't make it expandable on all their platforms. For Christs sake, it's 2021! Anyway, I digress
Synology tech support is average at best. They're friendly, but you never get anything solved on the first call, and I guess it's probably the norm for tech support, but they cant' help with anything that isn't already documented. Well, I've been a computer professional for 23 years and have a pretty good grasp of how to use google, and can figure things out on my own fairly well, so nothing irks me more than when I am working with a problem, or a bug, and there is no resolution on line in google, and I have some tech support person asking me basic questions and clearly doesn't know their sh** and is reading from a book. Come on Synology, endeavor to be better!
I bought the DS220j though after much deliberation. First, I do like the UI. It's fairly intuitive and easy to use. There is a lot offered in the DSM package plus all of the add ons. And my DS216j has been a solid performer! I did knock it off of a shelf and in doing so I destroyed the disks. Luckily, I had backups scheduled and was able to restore from my Amazon cloud storage. Which by the way, I'm not exactly happy that Synology no longer supports Amazon cloud storage and instead now forces you to Amazon S3 or others. I was getting 5TB of storage for about $80 a year and now all the available options are much higher. I went with Synology C2 storage, but even that is $60 for 1 TB.
As for the speed and lack of expandable volatile memory, I use my NAS as, well, a NAS! Oh, and NVR too! But I'm not using it for the host of other applications it can run. It's not my domain server, I'm not running a web service off of it, or a database server, or media center, etc. I store my files on it. A centralized storage location for my home. I have 27 years of digital pictures (older ones scanned in of course), I have about 500 cd's worth of mp3's on it, I store video from my go pro and from all of the movies of my daughters childhood that I digitized, I store my documents on it, and with the NVR I store up to 500 GB of video from my security cameras. Sometimes it's a little slow when I use the UI, but it's never horrible and honestly, I am in the UI probably less than 2 hours a week total.
There's' another reason why I don't use my NAS for all the other things, and that's security! My NAS is on a VLAN and 2 firewalls (my cable modems firewall, and another router and firewall on the VLAN). When you start opening ports for remote access, web servers, media servers, etc., you start making it more and more susceptible to intrusions. So, this is my NAS, my network attached storage system, and it's there for me to consolidate all my documents, past, present, and future. If I want to the other functions, I buy a pi4 or something similar and run things in dockers on isolated VLANS over VPN, etc.
I do think that I'll get one more Synology NAS in the next couple of years, probably a 4 bay + model, and for that one I might expose it more and use it for different functions. My elderly mother is getting the DS216j that I'm replacing with this DS220j, and I will be running the NVR at her home with a security system, and will likely add the DS4##+ later and use it as the backup location for my home NAS and my mothers and eliminate the $60 yearly fee for limited storage. I'll likely locate that NAS at my sisters so that all of the NAS's in my landscape are geographically distributed to prevent loss from a single event. And for all of you that have never had a NAS and are considering adding one, isn't that kind of the purpose of a NAS? Centralize all of your data, back it up often and remotely, so that you don't lose all your family photos, videos, documents, etc in a fire, or a tornado, or a hurricane, or a flood, etc.
Seriously, I have never understood why you would want to run all those other services on your NAS. It's capably, but there are other and better platforms for running other services. Including running things in a cloud environment and letting a dedicated team manage infrastructure and security for you.
So, buy this NAS. It's a good price, and it works exceedingly well as a NAS! Don't worry about the lack of memory and just don't use it for all of those other things. Let it do one thing, really really well!