Welcome to the Forum Mark -
Okay, first things first, what is it you are looking for this weapon platform to do for you? Plinking? Zombie Defense? What?
Because the TDI Super V and an AR-15 in 5.56mm are two COMPLETELY different applications.
I have handled the Super V and I like it. It's on my list of weapons to add to my safe, but it's not my first choice for a good SHTF battle rifle. It would make an excellent CQB weapon, or an urban environment, building to building weapon - plus it would be chambered the same as my 1911's - so I would only need to stock one kind of ammo. Huge plus in my book.
Having said that, the ammo for an AR in 5.56/.223 can be found just about anywhere ( gun shops, stores, sporting goods places, National Guard armories, police stations ). In the event of complete and total societal collapse, that would be a valuable luxury to have, the ability to procure more ammo....