It is odd that we have people flying in a 429 every day and nobody has reported any 'cacophony' above 90 knots. The owner has been happy with the noise level in the rear. Jesusnutt, are you sure your evaluation team actually flew one?
The extra 500 lbs will be a welcome addition as soon as the FAA accepts it. I never felt that it had a weight problem before, but extra weight allowance is always welcome.