I can't give you direct comparison ratings of the KJW and WE versions of the P226.. but i do own a KJW P229 (snub nosed compact version of P226) as well as a KJW M9A1. I also own a WE baby hi-capa 3.8. I can only speak directly of the manufacturers.
All of mine are propane powered.
KJW's generally are a solid gun, for the money that you pay. WE is a bit cheap in appearance and parts in comparison. I had to spend a bit of time tightening down screws, bonding loose components together (ambi-safety) and lubricating out of the box. Never an issue with my KJW's out of the box. Mag availability should be better for the KJW P-Series, as they are fully TM compatible. I don't know if that is true for the WE version.