I seem to recall that it was more a bad batch kind of thing.. I think they've always been pretty popular over here - and what I've seen of them running anyway was pretty convincing..
I only found out about the Sirio deal because I told another guy about the Fire 11 deal, and he was like, nnnnaaaaa, Sirio is so great, lasts forever, huge power, etc etc.. There used to be a guy here at rctech who was really big on Sirio engines.. - somewhere in Europe.. Forget his name, and haven't seen him around lately..
ps I HATED my (Sirio-built) Orion .24...