There is only one thing wrong with Easyjet and that is that they do not assign seats. Why they don't is totally beyond me - especially given they could charge for it.
The speedy boarding/boarding by priority only works where it is administered properly and where announcements make absolutely clear to passengers what the process involves.
Ok at LTN or STN but forget it at Barcelona, Nice etc where the ground staff don't seem to understand that the system exists.
It is a shambles - but the airline won't be told. So until they change the system I don't travel with them unless I absolutely have to.