When we edited the Mountain guide, we had the policy that a climb had have been repeated and confirmed to get 3 stars. Looking at the list of 3 star climbs in the Climb Search, I'm not sure this is true for these harder climbs:

Mind's Eye 70m 24 The Columns
Mildly Amused 35m 25 Bulging Buttress
Wootang 45m 25 Teardrop Gully
Completion Backward Principle 27m 26 Rockaway and Amphitheatre
Once in a Lifetime 55m 26 The Columns
The Colour of Magic 24m 26 Teardrop Gully
The Fifth Elephant 25m 27 Rockaway and Amphitheatre
Blubber boy 15m 29 Ferntree
Cheshire Cat 25m 29 Lost World Area
Kick Start 12m 29 Ferntree
Future Shock 8m 31 Ferntree

Anyone besides the first ascencionist want to vouch for their quality? Tony's concise definition of 3 stars in the intro of the guide is "An absolute ripper, a 'must do' climb."