tomthiel,
I share your concerns about "pro" vs. "high-end" cable controversies. I've had a chance to compare Belden 1800F XLRs to several "mid-end" interconnects, and I much prefer other cables to the Beldens. In my system, the Beldens are a bit harsh sounding, with lack of fullness in the bass and an overall lack of refinement. I haven't listened to the Benchmark XLRs, but they apparently use Canare Star Quad L-4E6S wire with Neutrik connectors. In reading cable discussions by several pro audio folks on a pro gear forum, I've noticed that many of them prefer Grimm TPR to any of the Mogami, Canare, or Belden wire, and some seem to feel that star-quad XLRs don't sound as good as other geometries in situations where going all-out to reduce noise is not a major requirement. Lately, I've seen positive comments about Vovox unshielded wire and a new cable from GhostCables designed to sound better than Grimm while not costing as much as Vovox.
As far as long XLRs go, I may try a Grimm TPR pair or possibly the new GhostCables XLRs to see how they perform compared to my current Cardas Clear Reflection XLRs. I'll post some comments if I decide to invest the $150 needed to buy an 18-foot pair of "pro" XLRs. I guess that's a pretty small investment in the interest of advancing my own personal home version of "cable science."