Of course, there's a killer 18 on clearance at Madisound right now: Aura NS18-992-4A. It has less xmax than a Maelstrom-X or LMS Ultra, but an underhung motor, and IMO looks better than both with the metal cone and pointed dustcap.
Having had most of the high-performance 18's myself (Ava18 -> Maelstrom-X -> LMS Ultra -> back to Maelstrom-X -> NS18), there isn't one I would pick over it if prices were similar.
There are probably a few Maelstrom-X's and other powerful 18's floating around, if you ask nicely. I might even know of one...
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