Scott, in the event that a person made a purchase of their front, left, right speakers sometime ago and that line is no longer in production (e.g. B&W Matrix 801, 802, 803, etc.) - what is your recommendation? Should the prospective buyer go to Audiogon to try and find matching surrounds or try to find another model from the same company with a similar drivers - particularly the tweeter. An example would be matching aluminum domes w/aluminum domes, ribbons w/ribbons, kevlar cones w/kevlar cones, etc.
It could be very expensive in the case of B&W to fully update from the older Matrix line to the latest Diamond line to use an example.