My only first-hand experience with Synology devices is their DS209, and it was pure joy to work with. I decided on Synology after researching many of the NAS devices currently available, with a focus on high performance.
The real shining star is their DSM 3.0 software, which I only fully came to appreciate after having a chance to use it. When you log into the web console, you are presented with a basic desktop environment implemented in AJAX. It's extremely responsive, and very useful for exploring the myriad options available. All of their NAS devices use the same software, and no features are artificially locked out. This means that even entry-level devices have access to powerful features.
For any entry level user, and even some power users, I would absolutely recommend Synology. I am even considering buying one for myself (an IT professional) because sometimes it's nice to have something that "just works" (as larsks said).
PS. I am not affiliated with Synology in any way, I just love their products!