Worthy post.For line-level signals, only two things matter: durability and shielding. Shielding keeps interference at bay. Durability gives you something you can rely on. If the shielding is good and you're sending a line-level signal, every XLR cable will sound exactly the same as any other.
Steer clear of the really cheap stuff, because it's often not very durable, and sometimes the shielding is skimpy. Any XLR cable that's medium-priced or above will do fine.