Not a significant surprise to me that the squeezebox's DAC is as good as or even preferred over the Benchmark. I've never been impressed with the Benchmark Dac. I have not heard the Antelope, but have read good things - but then again I also read a lot of good things about the Benchmark and after hearing it couldn't believe the positive comments.
Same thing with the Rega original disc players - lots of glowing comments about how great they are. When I finally had a chance to listen to one, yuck, I couldn't believe what I was reading by others vs. hearing myself.
With DACs, I am of the belief that so many of these "new", latest greatest chip-set dacs are put together cheaply and the key components of a good audio component are just neglected.
Every audio component needs to have a good power supply to sound its best (that means weight and cost). Same thing with other parts and its circuit design. Just having a good chipset doesn't make a good DAC, in fact, I have heard many great DACs with older chipsets (but great power supplies, circuits, outputs, etc. . . ) that just blow away some of these new DACs that only consist of the "newest" chipset.