A lot will depend if you are going to transcode video.
Very roughly speaking, for a single full-transcode of a video, the following PassMark scores are a good guideline for a requirement:
1080p/10Mbps: 2000 PassMark
720p/4Mbps: 1500 PassMark
the cpu is good enough to transcode one 1080p stream, but my main concern is the case. It only has space for 3 HDDs. If these limitations are not a problem to you, then by all means go ahead and buy it. The good thing it that the cpu is very low consumption. Will this be working as a server/player combo, running a desktop os, or as 24/7 server (maybe running xpenology?) ?