Majik DSM - Synology DS 214+ or 213+

Looking at replacing my NAS for my Majik DSM:
has anyone got any experience of the Synology DS 214+ or similar systems?
Two advantages of the system:
Low power consumption.
And it is possible to expand the available disk volume (2x max 4TB possible, max 4 TB with RAID) by adding a second device or disc drive DX 213 (another 2 x max 4 TB getting 4 TB with RAID).

Thanks a lot and best regards

http://www.synology.com/en-uk/products/overview/DS214+
http://www.synology.com/en-uk/products/overview/DX213