I've got money to do a killer DIY pair, and I'm down to a decision point, and that is: LS-types or OB types. After Danny's original Alpha LS pair, and what I'm reading about the new LS series, I'd probably pull the trigger on an LS. BUT, earlier this year, I sliced and diced the MDF for a local customer who had another designer (okay, it was Rick Craig) design a high-end OB speaker; open baffle MTM on top, attached to a bass bin. M's were Accuton C82's, tweet was BG Neo 3, woof for the bass cab was Seas W22EX. When I heard them, was I impressed by:
dynamics? nope
extreme LR world-class soundstage? nope
extreme depth of soundstage? nope
neutrality? YES, LIKE NEVER BEFORE!!!! OB could convert me to a "Chicks singing" fan

What am I saying here? Danny knows that I've been on a DIY quest for speakers that can accurately reproduce a LARGE ensemble and its incredible dynamics. I play in the Austin Symphonic Band, a wind and percussion world-class ensemble of 85 musicians. As yet, I haven't found a speaker that can reproduce our sound at concert volume levels without intrusive distortion. Closest was Danny's Alpha LS.
But, I am in confession mode here and I admit that the El Ultimo speaker for me would be an OB design with enough drivers to deliver DYNAMICS. So, Danny, I throw down the gauntlet, and suggest a name for El Ultimo: OBLA-D! An homage to the Beetles? ("Obla-Dee, Obla-Dah, Life Goes On..."). No: Open Baffle Line Array - D (Danny).
Go for it, Danny!