I have worked with the mac quite a bit. I got the cut before a lot of people got it.
Its true it does not seed well but if you know what to cross to it and hunt those out a better keeper is definitely possible.
As far as herms go I have not experienced that. We made a ton of F1s directly and there was no herm reports. A few mutants but I have seen some beautiful plants come off the Mac.
I have a MAC x Kumquat cut (Kre8) that is simply amazing and bullet proof, ..
My MAC1 cut is a bitch..The worst mom I have ever kept in terms behavior..honestly feel like killing her most days. But I will venture into the auto x photo F1 and see if there is any promise in terms of working her further...got other irons in the fire at the moment.