Mac mini audio through optical or USB or??

I have charged headlong into PC audio and while it is sometimes a little perplexing, I am very pleased with the sound quality and accessibility to thousands of songs instantly. I have found my Benchmark DAC 1 with a PC feeding it is superior to all of the $2000-$5000 players I have owned.

I have tried hooking my Mac mini up to my DAC 1 several ways, using a Squeezebox via coaxial, a Hagerman HAGUSB to coaxial, and using the Apple's built in optical output.

Normally in the past I have never been a huge fan of optical connections, however using the optical from the apple I can select 24/96 output from iTunes and the sound is surprisingly very good, however it lacks the last bit of refinement and air I get from my Bolder modded Squeezebox and seems like there is sometimes a whiff of brightness that creeps in at higher levels.

The HAGUSB will only accept up to 48khz so I have to set the Apple's output lower, and there seems to be somewhat less dynamics and detail compared to my other two options.

If anyone has any of their own experience with this please share, I was going to sell the Squeezebox and simplify a bit but I prefer the sound quality I get from it over the other two options. The apple optical out is fairly close however, and if anyone has a tweak suggestion it may be able to win out.

Also on a side note, I am hoping some of the rooms at RMAF will have PC audio this weekend as well, if you know of any specifically planning to exhibit please let me know and I will be sure to check them out.