Are there benefits to separate preamp and dac?

I have some Quad 12l Active speakers, and need a preamplifier to control them. I am debating between a reference Marantz preamp and separate DAC, or a Benchmark DAC1 HDR...which is DAC and preamp.

What I'm trying to understand is which setup would be optimal sonically. The separate components are likely better at their dedicated functions, however, the combined unit does away with a signal path between components.

Looking for input on the sonic benefits and negatives of each setup.
Thanks in advance,
Mot