Sorry if I wasn't clear. I just got off the phone with Wilson. Of course they say there would be a huge difference in quality. The tweeters we are talking about are the exact same model that Wilson has modified for their speakers. The difference is the "of the shelf" model has an oxide coated titanium diaphragm while the Wilson driver has no coating on it's titanium diaphragm. The Wilson model also has an extra magnet and a different surround (rubber instead of foam). So the two drivers are fairly different even though they start out as the same driver.

Hope that helps clarify things.
Mr Vinyl