Digital Coax, optical, or RCA for use with my Bluesound Node player?

I have a Marantz 8805 and use the Bluesound Node 2i to enjoy my music on. 
I’ve listened to the Node with both optical and rca and actually prefer the node using the RCA connection. 
I’ve never tried a digital coax cable.

Which cable would you choose?
I'm very happy with an Audio Envy digital coax from my Node 2i into the dac in my Marantz 8005 SACD.
If you're streaming over 96kHz then I'd stop using the optical and move to digital connection.  There can be a bandwidth limitation with optical cables.  
You'll do a lot better with a 75ohm digital coax vs. RCA interconnect. What is your budget?

I've auditioned quite a few. Acoustic Zen was very good.
Cerious Technologies makes a good S/PDIF cable with a return policy.
BTW, the recommended length for digital coax is 1.5 meters. 

Analysis Plus "Digital Crystal" COAX 1.5M

Continuous Cast Copper (solo crystal copper) braids, hollow oval design. Demo’d and owned various AQ, AP, Cardas in 1m and 1.5m and preferred AP Digital Crystal. Pricey, but this to a good DAC and wallah!
@todd1010 So how does your new cable sound? Want to step it up again on your Node? VH Audio sells a shielded two conductor power cable in bulk that is very good. For the ends from VH Audio as well, buy Furutech plugs. I don’t have photos of my system but I did post a pic of the cable I’m speaking about. I think you’ll be surprised of the improvement a better PC will make on your Node. Well worth the upgrade.
Bluesound did replace my unit with a new one and a new one I mean a Node 2I even though I had a Node 2. 
I haven’t received the cable yet so can’t comment. 
I already have a Audioquest power cable on it. 
For digital audio applications, coax (RCA) is generally considered superior to optical (Toslink). Blue Jeans Cable offers some at very reasonable prices.
I just received a Cambridge Audio CVC v2 due to my ARC CD player, used as a transport, crapped out (yes I tried to have it fixed to no avail).

So, I'm interested in a new RCA-RCA digital cable to connect to a Bryston BDA-3.14.  
Seems I'm hearing (no pun) good things about Analysis Plus. 
I'm leaning towards the "Digital Crystal" but would like the OPs thoughts
on the  Audioquest Carbon digital coax when you receive it. Thanks.
Regards, Barts

I’ve read that the nodes dac will support mqa (tidal), so I’d stick with the rca connections if you’re listening to mqa tracks. 
Try the silnote digital coax. Extremely well built (US) and sounds beautiful. It’s on sale right now for their 10th anniversary. Great deal!