Anyone every tried Audio Nirvana single driver speakers???

I have always been curios by the single driver speaker but never heard one. I see brands like Omega and others. I have a el84 20 watt amp sitting in a closet that I can use with it. I was just wondering if any of you guys have ever heard them, built them or own a pair? 

I understand the bass may be lacking and the can be bright but also hear they are very involving and musical. I was considering the 12 or 15 inch driver in a 5.6 box. David at Audio Nirvana said it will compete with most very expensive speakers out there. I just know nothing about there type of speakers, I've only heard them through my iPad if that says anything. Any advise would be appreciated, am I heading down a bad road?