The whole AF thing is pretty recent anyhow.....from what I've read it's a ruderalis derived gene that is responsible for the autoflowering. There's a few breeders playing around with them.... JointDoctor, MDanzig, Lowlife and others.... but again, from what I've read many of them are unstable and don't autoflower, or dwarf consistently.
I've grown LR2 a few times now and I really rate the smoke. Not tried any others, and don't really have any inclination to try....but the taste of the LR2 is lovely....handy buzz too...