@bpoletti
Changing even a single component ( pairs in this case - left+right channel) can, and does, make a huge difference in sound. In many cases more so than going from bad speaker cable to good ones.
There is no "design flaw". A good analogy would be a motor car getting a new, and much better, tires. The car is still the same, but a good set of tires can increase mileage, shorten brake distance, improve handling and make the vehicle safer. Same for an amp. It still the same great amp as before but it's a little enhanced, a little improved.
It costs a couple of $100 to upgrade caps vs. the tens of thousands new pre - amps will cost. New pre-amps, which incidentally will have the same or similar mediocre capacitors we are replacing in the Canary pre amps; meaning we'll be back at square one looking to upgrade capacitors in our new pre amps.