Which DAC is better?

It isn’t too difficult to beat the dac of the node, but the node is great for streaming and the UI is top notch. 

+3 that the Hint DAC will likely sound better than the node dac, but as others have mentioned there are also many $2k standalone dacs that will take the performance higher still if you want to grow down the road. Happy listening 

why ask if you can just try it?  trust your ears and make the effort to decide

Use a COAX cable yo your preamp. Better than optical. Don’t use the default rca cables. Please.  

Just go out and get a dCS Bartok and never wonder again. 

I have the Node 2i and would be very happy with the internal DAC if it was my only option but I am currently running it through an external DAC to my preamp. I do find the DAC in the Node 2i to get better at higher volumes.
As others have stated go with the SPDIF Coax cable from the Node to your preamp to test the DAC in the Hint. You won’t get the higher res transfer from the Node using an optical cable.
You should be able to also connect the Node from the analog outputs in the Node to the Hint and switch inputs back and forth to compare the DAC's one after the other.