Define your personal 'best' in regards to diamonds. Does your best include a great deal? Is your best going for a D IF? What do you define as the 'best' when buying a diamond?
What's best to me is: unusual, striking, difficult to duplicate. Which is why I'm drawn to Asschers (whose differing, changing patterns are all like fingerprints to me) ... and antique stones that aren't cookie-cutter super ideal headlights. Also: colored diamonds. Rare!
D IF's do nothing for me. In any shape. Cold ... barren ... ice.