When comparing Synology Diskstation vs Raspberry Pi, the Slant community recommends Raspberry Pi for most people. In the question“What are the best media centers?” Raspberry Pi is ranked 1st while Synology Diskstation is ranked 6th. The most important reason people chose Raspberry Pi is:
You can use it for surfing the web, play retro games, and host your own.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Complete multimedia platform
The DSM includes packages for audio, video and picture services. You can organize all you media within the Diskstation and access it with your browser, the network, FTP, WEBdav and much more. You can even stream your media via the Internet.
Pro Easy-to-use interface
Every Synology Diskstation is shipped with the DSM, the Linux based interface. You can access it via your browser and configure and administer the Diskstation. There are a lot of different features for a lot of problems who want to be solved.
Pro Enterprise features like LDAP and Active Directory support
There are a lot of features that helps you to implement the Diskstation into your IT infrastructure. The Diskstations support LDAP and Active Directory to connect to existing servers or host a new one.
Pro Access your data everywhere
It doesn't matter where you are: you can access ll your data via the internet using the Synology Cloud Services. Another feature is the Dropbox-like client-based sync between your Diskstation and various devices like your Mac, Windows PC or even your smartphone.
Pro Not just a Media Center
You can use it for surfing the web, play retro games, and host your own.
Pro Customizable
A lot of Media Center OS to choose.
Cons
Con Lack of 4K support
The max video output is 1080p.
Edit: Raspberry Pi 4 now supports dual 4K displays. More at : https://www.raspberrypi.org/products/raspberry-pi-4-model-b/