I don't think the quality is very consistant regarding Feigao motors. I have one 8XL that I have been running in my brushless 1/8 scale buggy for over 60 hours total run time with no issues. I had another one come part in less than 30 minutes. Feigao motors are great for getting you into brushless on a budget but you bascially get what you pay for.
Magnet separated on my 8XL.