A few differences - some will see them as pros, others as cons. As such, naturally there will be a divide of people that prefer a particular company. Exactly the same as why some BA crew prefer LGW and some LHR. There is no "better" company or job, but lots of varied factors.

easyJet - Very few nightstops, so you're in your own bed every night. Many more bases around the country, rather than just LHR/LGW. Higher take home pay (esp with commission). Just one simple service. Excellent staff travel within Europe

BA - Worldwide travel, with lots of long trips. Lots of varied countries, but away from home a lot. Lower take home (assuming ex-MF). Many aircraft types and varied services from Buy-on-board up to First Class. Only bases in London.