The Tour magazine does a wheeltest measuring aerodynamics of wheels, this is a list of watts spent for a given wheel at either 25 or 30mph listed from best to worst: Ritchey Carbon, Easton, Vuelta and CKT all use an undimpled 404 rim.

Zipp 808 18.1
Ritchey WCS Carbon 19.3
Hed 3 19.7
Vuelta Carbon Pro WR 20.8
Easton Tempest II Carbon 21.6
CKT Splendor 21.7
Mavic Cosmic Carbone SL 21.9
Shimano WH-7801 Carbon 50 22.9
Campagnolo Bora G3 23
Rose Aerospoke 23.0
Corima Turbospoke 23.1
Bontrager Race X-Lite Aero 23.4
Fulcrum Racing Speed 23.7
Gipiemme Carbon 5.5 24.1
Tune Olympic Gold 24.1
Shimano WH-7801 Carbon 24.4
FRM FL-R 23 SD Aerolight 24.6
Corima Aero 24.7
Lightweight Obermayer 24.8
Xentis Mark 1 25
Citec 3000s aero 25.5
Shimano WH-R560 26.1
Lightweight Ventoux/Classic 27.3
Campagnolo Eurus 27.8
Tune Skyline 28.1
FSA RD-600 28.7
Mavic Aksium Race 30.0
Citec 3000S 30.6
Ambrosio X-Carbo 31.5
Campagnolo Hyperon 32.1
Mavic Ksyrium ES 33.2