Never had a WE, but Ive had KJW Glocks and TM Glocks. If you dont count the plastic slide, TM is way better.. Looks better, feels better, shoots better..
TM mags seem to be Godlike! Never had issues with TM Glock mags, while 3 out of 4 KJW mags started to leak..
I've left 4 fully filled TM 5-7 mags for about 8 months, never leaked. No leaks at all! Still full of gas, I emptied the whole mag..
KWA mags seems to be really good too, but I've only had KWA CZ75.