The original QS4s used a different tweeter than the rest of the Axiom line and later QS4s. The easiest way to tell the difference is if the tweeter has 4 screws around it or 3. If it has 4, it's the newer version, and I would feel more comfortable getting it. If it has 3, I'd probably go with a factory outlet or new QS4. There were other changes that made the v2 line, and before the v2s came out came the change to the newer tweeter.

I am the Doctor, and THIS... is my SPOON!