Too much favourtism, Swing shift with rediculaous start times are very hard on the body and mind. Spend 2-3 years on contract with limited benifits.
Come bonus time as a contract you are only worth the percentage of top rate you are, even after working your butt of for two years. (ie: if the bonus is $1000, the full time guy beside you get the whole thing, but if your only at 65% of top wage you only get $650).
Can't think of any, TBH
Not enough space to type them all