I think you and I are nearly on the same page here Pro. I know by the general populous most products won't reach full potential. What I have discussed is using that erroneous playing field as the benchmark for my judgement of DD. Under imperfect circumstance, I have seen many other products: including SSA, Kicker, RF, Memphis, MTX, B2, Jenson (what?) all do better relatively to their build than any of the DD builds I've seen.
Of course there is error in all of these because they weren't done by some of the better box builders in the area. By your account, is it safe to assume that every single DD install had measurably more error than the other brands? I think not. That is where my beef comes in. I'm not saying I don't like DD products because they aren't the loudest vehicle I've heard. I'm saying I don't like DD products because every install I've heard should have been louder for what type of install it was. I was going to give them a personal try to eliminate the error part of it, but $1600 at cost? Give me a break, I can find a better woofer for less paying retail.