Originally Posted by MSPeconomist

On the first reservation you were just making a Schengen to Schengen connection in AMS, while on the second you went through passport control to enter Schengen. Arguably it didn't matter on the first, although SkyPriority doesn't seem to matter for the intraterminal passport control at AMS (unlike CDG). LHR and CDG would have many more customers checking in, checking bags, and going through airport security (for the countries where there's a separate line for SkyPriority security like in AMS and CDG for instance).