As a straightforward example of where additive solutions are not the smart way, consider again my earlier comment about the $100,000 amp combo actually delivering $10,000 worth of sound quality, because glaring weaknesses are not addressed. So the owner admires the bling of his setup, but is still not happy -- he's not getting $100,000 of sound quality. He says to himself, Right! I'll have to get the $200,000 combo to up the ante, and he does, but, lo and behold, 90% of the possible quality is flushed down the toilet yet again, so he actually gets $20,000 of effective sound quality: he's still not a happy camper ...
Desperate now, he says, I'll have to go for the $400,000 combo!, and he pulls out the cheque book -- I won't bore you with the next bit ...
Me, I would be content in "platitude" land, by taking the $100,000 discarded effort, at a special throwaway price, subtracting the worst deficiencies so that nearly all of the 90% losses of quality are eliminated, and end up with close to genuine $100,000 sound quality, first go.
Methinks, I might be a touch more content than the other bloke ...
Frank