Better DAC or better Streamer

Streamer 

I believe the Nagra streamer is the same as the PlayBack Designs streamer that I had. The low end one for $3k. The Nagra DAC is also a PBD DAC design but with different boards than in the PBD DACs Andreas Koch of PBD mentioned the DACs in an interview and I read something about the stream online.

DAC for sure. There was someone comparing my $3k PBD streamer to the $13k or $20k PBD streamer and they could not tell the difference. Most likely because fibre was involved. PLINK in the PBD case but you can use something like a OpticalRendu for similar non-proprietary results.

DAC hands down.  I have a Chord Dave and it is huge.  I also have the Farad power supply for it.  I am not using mine now as I have gone Tube with Lampizator but in the AB the DAVE held it's own

Jerry

In streaming as with all audio the chain is only as strong as the weakest link, and in your case the DAP is by far the weakest link so get thee a good dedicated streamer.  You already have a good DAC, but using a DAP as a streamer in a high-end system???  No…just, no. 

I certainly depends on the sound character you want to change. If I had your system, I would want a more musical and natural sounding DAC. The DAC is likely to have a bigger change on the sonic character. The streamer will lower the noise floor, increase  dynamics and detail.