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

Since they are a manufacturer direct company (no dealer in the middle, adding another 50%, 60%, etc to the price tag), their speakers and subs can represent great value.

I had a pair of double impacts inside a larger office room for a while in my former house. I still have their 4-10 subwoofers, currently in storage due to lack of space. It is an excellent subwoofer for music and all other applications.

Echoing another comment above, their customer service is good.

I would call tekton he can build you what you want.there are some prominent people who have his speakers.yes they are bang for the buck.he can put the best crossovers you can get he will customize for you.the paint is fantastic.now they do not have furniture grade wood like my kharma,focal utopia,or several screws like my magico q7 but they weren't 30 x the price either.i have woofers he custom made that for sound I would put against the top of the line.he uses high end components if you want beryllium  componinents  if you want that upgrade.beryllium is light fast and responsive.momentum is mass x velocity and because it is light it's fantastic. I have all his top of the line speakers and find them great.just call him.enjoy the music and the adventure.

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.

Not sure how those Double Impacts were set up, but in my dedicated audio room I have fantastic imaging and they float a very large and accurate soundstage.  They exceeded the Magnepans I had at the time which were quickly sold once the DI's were dialed in.