I have several mates that have had kanai sirios and while they all say they are stupid fast they have all had breakages, bearings, cranks. I believe that sirio has or had a quality problem, however this is just my opinion. Having said that i have had 2 Evo 3 (one an STI) .12's have major bearing failures within 4 ltrs, so bad that i had to replace, bearings, piston/liner and head buttons, so this kinda backs up my opinion.