It has good depth/table numbers. Some people (myself included) aren't a fan of how much spread you lose with the AGS princess diamonds. Having said that, each of the prior posts is correct. I would try Good Old Gold - they are easy to work with, do not pressure at all and will provide ASET, Idealscope, Megascope, pictures, video and heart to heart advice. Then you can accurately compare not only your princess that you are thinking about but others that they hand select (or have in stock - 2+ you start finding less "stock" princess cuts). I think the idea of finding the diamond in the rough of the GIA's - ideal light performance - is a fun journey and you come away with a larger facing stone (not all the time, but most of the time). Often times you can also save a nice chunk as well. Oh, and if you have the GIA cert No. and where you found the diamond it is very likely that GOG can get that diamond in and analyze for you.
So I don't get yelled at, yes, AGS0 princesses (either Brian Gavin Signature or White Flash ACA) are EXCELLENT choices. They (i) carry a premium, (ii) are available in limited stock (if you have particular criteria requirements), and (iii) are cut quite deep (most times) and will face up smaller than a well cut GIA. My goal was as close to 70% on the depth as possible - GOG helped me realize on that in a diamond that outperformed other AGS0's. I was incredibly happy with their experience and would recommend them without hesitation. However, if you go that route, realize, it is more time, work and energy than just finding a great AGS0 and clicking "buy". I started nearly 8 months before I wanted to propose (the setting is now eating the rest of that time up).
1 final thought - do not buy without ASET/Idealscope and a jeweler you trust reviewing. Also, don't buy until you have viewed a number of different diamonds (even if only via video).