Solars get to stay Solars, which is as good as you can get. Terrestrials may become some undefined different thing when they reach Essence 9 and buy that medicine Charm 5 times. Abyssals can bypass the Neverborn in their pursuit of Oblivion and become direct avatars of destruction and murder. Sidereals get more esoteric Sidereal Martial Arts as they go. Lunars... well, Lunars get bigger animal shapes.