Sapim or Dt Swiss?
I have 622mm wheels with Sapim Strong spokes fitted with Sapim's own Polyax nipples that George also uses. The wheels are getting on for 9000km of rough tarmac use under hefty loads (they're on the bike I use for carrying my painting equipment, and a case of wine, and catfood, which really weighs), not mollycoddled, and the spokes are still as tight as a drum, never had a spanner on them. Not very elegant spokes though; the butt is short, not much tapered. All in all, a longlasting, workmanlike spoke, well worth the modest premium.