Nope, I've not tried Boulder Cables, and have no impression of how they compare with the ones I've tried.
However, as far as I'm aware, Boulder, the electronics vendor, does not make cables. In fact, Boulder delivers their Amps with Canare power cables (which work just fine by the way).
If I'm not mistaken, "Boulder" and "Boulder Cables" have no relations to one another other than the Boulder in their names ;)
Or am I wrong?