I am in the same situation. I looked at the Aurender N100 and it only has a USB digital out. It needs a converter to work with some DACs like my Audio Research DAC8. The Bluesound has a digital RCA out so it can easily connect to non USB DACs or USB DACs that require software. The SOtM sMS-1000SQ looks interesting. The digital version has both AES and RCA digital outs as well as USB.
dimora, I have a Synology NAS. How do you get from the NAS to the DAC? Do you use a USB cable? This sounds very interesting, can you tell me more about how this works?
Audio Stream has quite a few reviews and comparisons of audio streamers.
http://www.audiostream.com/category/players-streamer-reviews