So I give it an 8 because I think the horses are super well done, the world is amazing, I absolutely LOVE that family play is now a thing EA actually knows we want (so thanks for letting kids ride horses; maybe in TS5 you'll also let them do some actual magic :P), it really enhances farm gameplay, and everything just looks super gorgeous. Like really, the pack is just super fun to play with. I haven't regretted it over the past 20+ hours I've been playing it.
However, it's an 8 because I do think some stuff is missing like: (as always) updated Parenthood interactions, magic options (why can't we bind horses as familiars???), a place where you could keep horses if you don't own a ranch (like I feel like IRL you don't need to own a gigantic plot just to have a horse), etc.
It's just that these things really don't dampen my enjoyment of it so a solid 8. Very fun.