The game has many fewer options and decisions than the adult version but that works really well for the kids.
Played it with a few kids and adults on Thanksgiving. He really really likes the Ticket To Ride Junior. I haven't played the junior version, so I can't tell you differences. Only real issue is that by the end of the game keeping his attention can be a challenge.
But there's a lot of enjoyment in placing the tiles to build the cities. He's been playing effectively for a few years now. My 6 year old plays the regular/adult carcassone with minimal help (we've been playing the abbot/river expansions without the farmers) and he keeps up.