I'll be brief and honest. This pack is probably super if you play family life including focus on infants and family dynamics etc. I don't focus on those things, so it might me one of my less used packs. I just recalled that I never even tried the back carrier for bringing an infant with you... The world is nice, but without much extra. There's many lots, but I guess it all depands on what you use those lots for. I like CAS, because it brings a new fashion style (tiny bit weird, though, but something we did not have before). I'm quite neutral to this pack, and my biggest negative is the milestone system which mainly give plenty popups and clutters the simology panel, while I can't see how it influence on my game in any way other than graphics/UI. The system is probably good if you focus on all those small milestones - especially for infants, which I don't. I must add that the infants are very well made, occasionally I can sit watc hing an infabnt for a long time only to watch its movements and reactions, they are very good and I assume their chain of milestones feels very realistic too, for those into it.
As with TS3 Generations, I assume TS4 Growing Together adds more in the background than we can see. So there might be a few smaller improvements to the game that I'm not aware of.