MGOOF : Modern groupset on old frame

i just want to confirm that there's only one style of gxp cranks

must be something else,

• either your cranks spindle is already much used
  
• or your sense for "nipping" the bearings is too sensitive, when the cranks only spin one
  round when tipping that's more than usual when the bearings are full of grease
  
• sram recommends putting more grease on the spline, sounds stupid i know, works frustratingly well, shows the inferior design of that spindle design (still got 10 bikes with gxp cranks on them right now ;))