I've spent the past hour+ playing the game! At first I was horrified. All I seen was simplistic **** everywhere and it felt too bare, more than I was used to with anything. Take note before reading I haven't played TS3 in years, so I might mistake some "new" features as old ones.
With time, I got used to it. The world is more full of life (despite limitations of only being able to move within a certain block of the neighbourhood) and level of detail is shocking considering how easy the game is people compared to TS3. Willow Creek's sister neighbourhood 'Oasis Springs' was a bit more boring than the former, but both are very detailed and since I've yet to explore a lot of the place, I'm assuming I'm in for more surprises and subject to change of opinion.
Social interactions are the biggest surprise. They're more prominent and important than ever from what I have noticed. I used to always use social interacts as a means to an end (hooking ha up) and spam clicking "Chat", "flirt", etc but now you have to pay attention to the conversation to get the best out of it, one of my conversations took a horrific turn as one of the sims felt awkward and it was affecting their relationship progress as a result of the discussion. You can pick different things to talk about as a result, etc. It's very surprising and brings some freshness into such a feature that I've mindlessly taken advantage of over the years.

It doesn't really cripple you, though. If you like to give commands and skip forward, you still can, but you have less opportunities with conversations and emotions, etc.
CAS is just as it was before from the demo, clothing options are much bigger than the demo and the tools within this feature help you craft some amazingly detailed Sims. Hair options are much better than base game TS2 and TS3 from what I remember. So props to that.
Build/Buy mood is smooth and flawless!

Feels better than ever and the fact you can pick up rooms, etc means it ***** over your fav Sims titles!
Aside from this, there's still some missing features and the game does feel bare at times, and I admit to missing them and hope for their return but it still has the CORE Sims experience that I remember from playing from YEARS AGO. If you fell in love with that experience then I doubt you'll have any issues with loving this game (I'm betting that the majority of TS4 haters - who own the game - are new sims fans w/ TS3

) You can definitely feel TS2 vibes from this game and I feel that Maxis can unleash the game's full potential within patches and EP's some great content to expand the game and hopefully surpass that game.
I still miss the detailed UI from the previous games and think that the "organised" look is a bit too much with this game. Needs should be able to be pinned atleast. I shouldn't have to click them when I want them, how am I supposed to know if she needs ha pee time.
The Sims look much better, I agree!