I'll try to keep this short:
Create-A-Sim
Pros: The customisation really is brilliant. It's very easy to get started and get stuck into your first Sim, making them truly unique - nothing like what we're used to! My Sims could have crazy combinations for their hair, clothes, whatever. It's easy to add Sims, and to create relationships - and the game prompts you to do it before you save, so it's difficult to forget! Without a doubt, my favourite feature of the game.
Cons: I found it a bit slow to select styles - despite being over the requirements for both RAM and processing speed (admittedly, only just). I managed to persuade my father to order me more RAM later on, so I'll let you know if this improves! Also, I felt the clothing and hairstyles available were quite limited. Although you can customise to your heart's content, it would've been nice to have a few extra styles available.
Create-A-Style
Pros: Again, it's brilliant - you have complete control over what you want to do! It's nice to be able to copy that style onto all the other objects in the room, too.
Cons: It was a bit confusing to work at first! In addition to that, I had some trouble with getting styles to copy - but I
think I've got it under control now...
Relationships
Pros: I love the new way to select relationships: when you click on a Sim, you're faced with a pie menu as always - but instead of having "talk", "play", etc - you have "friendly", "romantic", "special" (interactions related to your Sim's traits), "mean", etc. It's a far better way to select an interaction - no more falling in love when you don't want to!
Cons: However, relationship building can be difficult and very time-consuming. After three days, my Sims were "romantically interested", their relationship bar was full, but no matter how many romantic interactions I queued up, the option for "going steady" didn't appear! It popped up briefly, but not for long enough for me to select it! So now, my Sims are stuck.
Buy/Build Mode
Pros: It's laid out in a far better way - each room gives you a layout of that room with all the objects the game thinks belongs there (for example, the bathroom has an image of a toilet, sink, shower, bath, curtains, pictures, etc) and you just select the object to place.
Cons: None as of yet! The only thing I can think of is how the UI actually
looks - it reminds me a lot of the interface in The Sims 1, which for me, seems like a step backwards.
Time
Pros: The days seemed quite long to me, so I was able to do everything I wanted in the morning and head out to the park in the afternoon.
Cons: It takes
ages to do simple tasks - if you thought it was painful when your Sims took an hour to go to the toilet in The Sims 2, it's even longer in The Sims 3! I got my Sims up at 5am, in time for Travis' carpool at 8am. This was enough time for him to have a bath and go to the toilet. Breakfast was on the table but he ran out of time!
In addition to this, a major downside about having long days means that your Sims are lalalalatered by 7pm! I kept my Sims up until 10pm because 7pm just seemed far too early, and they got negative moodlets due to being tired! All they'd done that day was sit on the sofa talking, watching TV or cooking.
Furthermore, the fastest speed setting seems incredibly slow - as do the others. I was sitting there while my Sims slept at night not knowing what to do! It took
ages to reach 6am again - so long that I managed to leave it on Speed 3, go downstairs to get a drink and a snack, and return before it was even 4am. If I had done that with either of the previous games, my Sims would have died by then!
That's really all I can do for now, I'm running on a low-spec computer so it's difficult being able to bear playing when it's slow and the graphics are so bad (possibly an exaggeration: everything is on low or medium, though). Hopefully, I'll enjoy the game a bit more in a couple of weeks when I've got a new video card and an extra GB of RAM!
For those who will be running the game on a PC that is either minimum spec or just over the requirements,
don't expect wonders. It can be a little frustrating at times, but the game is enjoyable, which will hopefully make up for it!
For anybody who is on the minimum for RAM, I really advise you to upgrade. I'm on 2GB, which is 0.5GB above the minimum, but I found The Sims 3 using 1GB
alone!
Overall - a good game, but it hasn't quite impressed me enough for me to prefer it over TS2 yet.
Edit: ... I realise I failed on the short thing.