I would like to hear a reply on this as well.
Indeed capacitance has been a major factor in how effectively some of the amps i've tested have played back speakers.
This big Coda 10.2 i tried once had enough reserve to playback for a second to two AFTER shutting the unit off (longer at lower volumes).
That's alot of reserve. I believe they had typically used about 120,000 uF in a Class A/AB amp.

"Those who preach the myths of audio are ignorant of truth."