Will use this thread to update anyone interested in my experience with the Platinums.
Today I replaced the 64 screws holding the 8 woofers with heavier-duty wood screws. I also added some speaker-seal material to the edges of the woofers. I may do the Dynamat mod on the woof baskets later on, but this should for now as far as the woofers:
The 6 screws holding the rear basket were also replaced.
Per F1nut's suggestion I added extra right angle braces to the bases and placed a 60 pound bag of sand on each:
Tomorrow I plan to work on the baffle finish (try to polish it) and on replacing the grill fabric.
The sound continues to improve and impress me. The imaging is particularly good, and the bass makes a subwoofer unnecessary.
Me happy,
OBG