Has anyone here had any dealings with Tekton, particularly their subwoofers

It all depends on your expectations and how high your bar is. I briefly owned the original Pendragons a few years ago and recently had a chance to spend a weekend with the Double Impacts. If you want a speaker that can fill a room with sound effortlessly at a relatively inexpensive price, look no further. But if you value imaging, a 3d soundstage and refinement, there are better choices. 
 

No free lunch or giant killers here. For my taste they are only “ok”, but not nearly as bad as some here would lead you to believe.

That’s funny because we put some Magnepan LRS speakers in directly after the tektons and both felt that bass and dynamics notwithstanding, the Maggies were the better speaker. I’m not slamming the DIs, they were competent at everything, just not great.

Is Corelli Carbon Miller?

I’d say the answer to that question is no.