I prefer going through the agencies as the contract rates are higher however if You can negotiate Your own contract then You can also take the agencies cut and have an even better rate.I worked at airbus through an agency called P+Z engineering based in Munich overall They were quiete good apart from the fact They made a mistake on My contract giving Me 30 days holiday when in fact I should not have got any I do believe this was a genuine mistake and in no way influenced My decision to leave which was based purely on the work I was doing at airbus.