I would say it's worth it to try it in my opinion. I was one of these players who started with TS2 and got to listening to most of the dedicated TS2 players on the old TS2 site on how they hated TS3 when it first came out. They complained about how the Sims looked ugly or how they didn't like the open world, etc, etc... So I had decided that I wasn't going to move to TS3 until I started watching some of promo videos for the game and ended wanting to try it out. And well since then, I love it. And even though I loved TS2 and have the TS2 UC, I have a very hard time going back to TS2. So I understand where some of the members are coming from who've commented about going backwards to an older game and how hard it is to get into them to get back into playing the older game/s. But what it boils down to is that you're the only one that can decide whether or not that you want to try it out or not. And I agree with some of them that have said about watching TS3 videos or other players gameplay to help you decide if this is the game for you.
Now I will tell you what I love about the game myself... :)
I love that we a variety in Supernatural creatures such as witches, werewolves, fairies, zombies and vampires. And yes, I know that TS4 has vampires as well. And yes, I know that some people may not like the zombies as they can be annoying and eat your unfenced in plants.
I also love the fact that we can create our Sims to be Supernatural Sims in CAS providing that you have the EP's to do so. Ex: SN Ep for witches, werewolves, fairies. We have Genies that can also be created in CAS if you have the Showtime EP... :)
We also have the University Life EP where we can send our Sims to the Uni world to further their education and get degrees. Of course when your Sim gets a job or profession that they got their degree in, they will start at an higher level of that profession. ex: Final grade C=level 2, final grade B=level 3, final grade A=level 4.
Of course we have World Adventures where we get 3 worlds to go and explore. But you only get 3 days for your vacation as the player needs to do assignments to up their visa points for longer stays. But of course if one has the NRaas Traveler mod, then you stay longer without having to up your Visa. Of course I am one that have the Traveler mod as I wanted to be able to visit other worlds in my game that was either in the EP's or store worlds or custom worlds. But of course in order for the travel mod to work, you would need to have either World Adventures, University Life or Into the Future EP's installed. Plus I wanted to take my Scooby Doo on vacation with the rest of the Scooby gang since pets can't go on vacation in a mod free game.
We also have a Create-a-pattern (CAP) tool that we can install on our PC's that allows us to create unique patterns that we can install into our game and/or share to the exchange for others to use.
Like this pattern on the top and mini skirt that I created in CAP... :)
https://i.imgur.com/zhqhf6dl.jpg
And then another TS3 player had given me instructions on how to take some of our in game pictures and put them on walls. But of course, the instructions are for placing pictures on the lower half of the wall and not the full wall like in this picture.
https://i.imgur.com/0Bha6Uwl.jpg
We also have a Create-a-word tool that allows players to build their own worlds. I have installed but haven't yet tried it as it is a bit complicated in my opinion. But we do have some very good world builders for TS3 such as Rflong7/13. Rflong goes by 7 and 13 on the old TS3 site as she has so many worlds that she's created as well as her own blog site for her worlds for download... :)
I won't bore anymore with other things that I love about TS3... :)
So I like what I said earlier, just watch some of the older promo videos as well as some of the "Let's Play" videos and read reviews from other sites before making up your mind about trying out the game or not... :)
Whatever you decide to do, Happy Simming from another Sims player... :)