I have started from the beginning with my new party in the ‘Perils of the Lost Coast’ Adventure.
The party is made up of the Paladin, Barbarian, Druid and Monk.
It is interesting because the balance of the party is quite different, and it isn’t immediately obvious how to play each of the characters. I am very familiar with the classic Fighter/MU/Cleric/Thief combo but these new four don’t exactly fit the same roles and need much more thought.
For example, the Paladin is basically a fighter-type but it seems both the Barbarian and Monk are better at thumping things. The Druid is sort of equivalent to a Wizard, i.e. weak with loads of spells, but she can pump her strength and dexterity checks. If she has an animal ally she is quite tough for a spellcaster.
New classes do have to be different in flavour and play-style, otherwise there would be no point, but it will definitely take some time to get a handle on them.
However, I have noticed they are low in intelligence skills, so essentially they are just a bunch of thickies roaming the Lost Coast looking for trouble.