The 75% is a travesty on EZY FOs, and until very recently, the company were recruiting DEFOs onto 100% whilst "loyal" FOs were stuck on 75% (which is 100% summer, 50% winter roster) because there were "no 100% positions available" for them to upgrade.
IE the company were screwing over the FOs who joined them as cadets on a terrible contract, and knowing the contract was so bad that nobody would accept it for Direct Entry, were offering the full time contract to new experienced pilots.
I believe now BALPA are forcing them to do something about all that, but not sure what or how long it'll take.
EZY is a great company to work at eventually, but the first few years are really $hit because of the contracts and general distain and contempt for their FOs. In the smaller and cheaper bases it may not be such a problem.
In & around the London bases, the early years FO contracts really doesn't pay very well compared to the rest of the UK airline market.