Hi Charlie! Glad to see you've joined the forum.
Although I've been using M-frame dipole subs for quite a while, I bookmarked your ripole build when you first posted it @ AVS back in 2013. I know markus @ AVS is getting unbelievable response - both FR linearity and decay - using two ripoles nearfield. It's an elegant design, and one of these days I'll make time to build a pair and try 'em out.
Ken