I have done a couple also.; My issues are as follows:
-Why cut back and layer with composite, it will turn matte finish just like they always have. The idea of this stuff was it polishes to a high shine and holds that luster over time. Composite doesn't.
-Staining, same issue as above, expensive, but my money is on using the Zr stains and light curing then covering with clear?
-I am still waiting for Dr's to request it as promised with all the mket'ing that was to be done
-only 8 shades, REALLY, I am not going to stain and cut back for 139$ a unit to match shades. I was told Dr can adjust with colored bonding resin, but really now we expect him to shade? Rght
-Has to put in with 3M's bonding kit, so if Dr has different system, they will say that is the issue, even though the flyer says must be bonded with adhesive bonding cement.
-Lastly, the stuff when able to prescribe the 8 shades especially for indirect MOD's or crowns is amazing to cut and polish in under 1 HR