Hi
Surfergirljen! Your ring shopping sounds exciting!
I think what
musicscrip may be referring to by 3 EX is the cut, polish, and symmetry (please correct me if I am wrong!). Tiffany will tell you what the stats are on those 3 factors if you ask. Obviously cut is the most important is should be excellent, which I believe all of Tiffany's diamonds are rated. The polish and the symmetry may not be, but I don't think it is a big deal. My fiance purchased my engagement ring from Tiffany's 6 months ago but we looked together. I had a ton of rings brought in and all of them (these were round brilliants and modified brilliant cushions (Novo)) had excellent cuts, and excellent - very good symmetry/polish. They were all fabulous!

My ring is triple ex but I couldn't visually tell the difference between mine and the ones that weren't.
As for color, my stone is an H and it faces up very very white and is a great value! I think it may be a high H/low G. We were originally set on a G and no lower as both my fiance and I could see a tint in the I color. When we were told the difference in price between my ring and a G-colored ring with the same specs, the G was almost 10K more!

I could absolutely not tell the difference between the H I have and a D stone that was on display, let alone between the G and the H. My ring is a VS1 but I would have gladly gone down to a VS2 if there were any available in the system with the same specs. Besides, my SO was tired of the multiple trips to Tiffany's so we went with the one I loved
Good luck with the hunt,
Sufergirljen! It's such a blast trying on all the pretty rings!