I would think the main thing that could go wrong with the drivers (unless you have a problem with your amp taking them out) would be the surrounds for the woofers and midrange units. Those can likely be repaired by Madisound. I seem to recall that there might be a former dealer in Iowa who has replacement drivers (he might have sold his stock by now), but as you assumed I would not suggest replacing the original drivers with off the shelf units.
Great speakers. I would check with the seller to make sure that they haven't had drivers replaced.
Great speakers. I would check with the seller to make sure that they haven't had drivers replaced.