Upgrading my streaming/digital system- what would make the most sense?

I used to output USB from my IMac to my DAC... Sounded OK to me. Then I got a SOtM SMS200 Ultra network streamer to feed my DAC. Everything opened up more and became both better controlled and Wider/Deeper at the same time.

Every once and awhile, I got back to iMac > USB > Dac for a few days to reconfirm the rightness of my now 4-year old choice. And it has always been a joy to return to the streamer. The iMac still runs the Roon Core, but the music comes via the SMS 200 ultra via the network. I also now use HQ Player and the SOtM comes stock the the HQP NAA built in.

I’m very happy with the SOtM streamer, but more than that I am just recommending the addition of a network streamer/bridge of sufficient quality rather than feeding your DAC from your Mac Mini.

Thank for this.
I hace started seriously considering upgrading what feeds the dac particularly as many more upgades have to come to the market since the last time I was looking into this as KNOCK1 pointed out.  And was looking to hear what others have experienced in their own systems.
I would love to try a GRIMM but I have $4-5k budget- so this well outside my means.  But I will look at some less costly alternatives- any suggestions?
I has considered a Small Green Computer with an ultrarendu but maybe I should consider a higher level solution.
Just out of curiosity, is a card/bridge as I have in the Moon, a solution that others like Bricast or PS Audio (previous dac) also offer, a major compromise to a separate streamer?

If the Grimm is beyond your budget, I would recommend the Innuos Pulse.  If you need it to be a server, too, the Innuos Zenith Mk3 would probably make you very happy.

Thank you!
I will definitely look into that.
In fact, along with the Innous I have started researching Lumin (U2/U2 mini), Auralic (Aries G2.1).  If I am not mistaken, and I might well be as I find that often the product websites are not as clear as they could be, the advantage of the Innos Zenith is that I would have it working as both a roon core/server AND as a streamer.   This would mean being able to replace my Macmini and adding a streamer rather than having to upgrade the server as well and adding a streamer. The other brands mentioned above, as far as I can tell thus far, offer streamers only, or streaming dacs, or all in one solutions (server, streamer, and dac). 
I understand that keeping all functions separate is probably the higher quality solution butt the Innous Zenith seems to be a well reviewed so I assume that the inherent compromise of having server/streamer is fairly limited (within the constraints of my budget).  In otther words it sounds like a potentially good solution vs replacing the Macmini and picking a good streamer.

This has all been very helpful to help me think about various upgrade paths so thank you everyone,  Now I am going to have to decide if to go for the dac upgrade first or upgrade what feeds the dac.

My personal experience: I found the biggest jump in sound quality was going from a Mac mini to a dedicated music server/streamer, which at the time was en entry level Aurender. My current server/streamer is an Innuos Zenith Mk 3, I'm using the Innuos Sense music app as I find it sounds better than Roon on the Zenith. 

I also have a Small Green Computer, which runs Roon for my Bluesound speakers around the house. 

The sound quality difference is noticeable between the Zenith/Sense and the Small Green Computer/Roon in my main system.