Sacred stones has the type of linear multiclassing I liked and introduced the pre-class units(ross,amelia,ewan). Maybe it's my sense of masochism but having another 20 levels to play out with a close to useless unit along with the standard classes felt really good to me. Ephraim and Eirika don't really differ that much in personality and honestly Ephraim's dialogue is more like a slightly laid-back Eirika.