How mean is this game? (say compared do Castles of Burgundy)
I would personally say it is much "less" mean than Castles of Burgundy.
You can still block people by taking what they want, but for the most part that is all you can do, and that is just normally playing the game.
It is hard for everyone to gang up on one person, and there are less ways to be mean to other players.
I never felt like someone was mean to me in Suburbia, just cleaver to stop one of my tactics.
I have felt people and luck where "not nice" to me in Castles.