I had JL's type 2 rep diffuser. I found the fitment to be only so-so.
There were gaps between the bumper and the diffuser that I found unacceptable. I got a type I diffuser (authentic VRS) from a forum member here and the difference in the fitment was night and day.
Just my experience.
2009 E92 M3 Le Mans Blau on Schwartz. DCT. RAC RG63, KW V3, Eisenmann Race, AP Racing, Vorsteiner GTS5 Front Bumper, Vorsteiner GTS-V Rear Diffuser.