Upgrades include: Experience drivers (higher output motor and lighter cone w/nanotech materials), Mundorf silver/oil capacitors (smoother, more pure upper mids/treble), damping compound applied to cabinet interior, and custom high gloss paint.
These are not after market upgrades, but original custom builds from Sean at Zu Audio. I’m the original owner and picked them up from the Zu factory in early 2010.
Rated 8 because they are over 1 year old (although they weren’t used for nearly a year), and for a small spot (approximately 0.10 x 0.05 inch) on the rear corner of one speaker where the gloss paint was scraped off, exposing the underlying primer (see photo). This hasn't been an issue for me since it’s only visible from the rear. However, I'd be happy to get some touch up paint from Zu and provide that to the buyer at no additional cost. Other than this one small flaw, the finish and all else is in great shape. One speaker shown w/o grill, but both grills are included.
Buyer pays shipping, insurance and PayPal.