The quality of XF seems to be better than NOOB these days.
I compared my NOOB PAM111 and the XF PAM000, XFPAM005 and found that
1. crown on the NOOB was more wobbly compared to XF
2. screw bars on XF were nicely polished at the opposite end and extend all the way to the end of the thread on the case (almost flush), NOOB's screw bars are way too short and the ends are badly done (seems there was more attention to detail)
I'm not sure if NOOB and XF use A6497 from different factories. The NOOB winds smoother and "looser" while the XF feels tighter and more snug when winding.
The NOOB crown guard has tighter snappy feeling while the XF isn't as tight but operates smoother when opening and closing.