They are more aggresive than the JWT ECU but still safe. JWT ECU's run super rich to avoid lawsuits. Ash and Ginn don't give a shit about going to court :) Zfromjapan also sells ECU upgrades. Pick the one that floats your boat.
:JWT is the safest upgrade ECU available. :Back it up with an AFC if you want to be smart... :infact, ANY ECU you buy should be backed up with an AFC and tuned on a dyno.