This ring looks great. By my measurements, the middle cubic zirconia (CZ) is 2.1 carats.  This is the maximum size for cubic zirconia before it strongly signals what it is, a diamond simulant.  Further, you can probably tell it's not a synthetic diamond because lab-created diamonds aren't white (at least not those that are mass produced).  Technically, CZ is a simulant, not a synthetic.

The way you can casually identify CZ is by either unrealistic size or by lack of brilliance compared to a diamond.  The worst cut for CZ, in my opinion, is princess cut.  The 3 main stones on this ring are cut with many facets (perfect for CZ), making it brilliant and far more difficult to distinguish from diamonds.  This ring is brilliant, with all the colors reflected through the CZ.

I see no flaws with the stones or the platinum plated band.  The ring can be worn with anything.  I strongly recommend this item.

Update January 8, 2014:

This ring continues to be a good accessory.  I would still prefer it a little smaller since 2.1 carats makes a statement.  If you see one just like it but a little smaller, that would be perfect.  Until then, this one will serve its purpose.