A few months ago, I bought a Bricasti M1 Series II. The built-in network card option was a major consideration that had me eliminate some other stellar DACs from consideration, if they didn't stream. I am extremely happy with the Bricasti M1 Series II. It is a DAC that would be at home in a $100K audio system. That is not to say that there aren't other DACs that wouldn't, but the sound is wonderful. The M21 with the ladder DAC may be even better (I haven't heard it, but will give the benefit of the doubt).
The M1 Series II is 13K MSRP with the network card, the M21 is 16K. It is worth it, however you may not get the most out of it, or any DAC (or additional streamer) without a quality network switch that can mitigate noise. I use an Ansuz A3 Powerswitch, that helps improve streaming audio. Even my tv looks awesome via the switch! My other source is an Audio Research Reference CD-8. I don't have a server, and use JPlay software on my iPad to stream from the internet.
If the decision is for Bricasti or any another DAC, it will likely be in your best interest that the budget is there for quality ancillaries, like audiophile grade network switches, audiophile grade ethernet cables, and audiophile grade power cables