Seasons-
The main selling point of this pack is that it adds changing seasons and weather to the game. It updates most of the worlds so that visual background actually changes throughout the year. The neighborhoods update every season so that you get seasonal amenities and activities at different times of the year. For example, in fall you can play/woohoo/start fires with leaf piles, or get refreshments at a cider stand. At different times of the year you can get hot (if you don't change into the new summer fashions), or cold (if you don't change into the new winter fashions) or rained on (if you don't use your umbrella). If you completely ignore the weather you can end up dying from overheating, freezing or being struck by lightning. If having seasonal changes in your game excites you, this pack is for you. If you have no interest, this pack is not for you. If you're on the fence, the build and buy, enhanced gardening features and the new holiday system are perks that you might enjoy.
Get to Work-
The main selling point of this pack is the active careers. The Scientist is my favorite. The daily objectives actually encourage you to interact with your co-workers, opening the door for workplace drama. I remember watching SpringSims do a let's play of a scientist and he went full on General Hospital with back-stabbings and romances. Also, at the higher levels of the career, a scientist is like a type of occult. Between special gadgets and serums, scientists have so many abilities a normal sim doesn't have. I also like the Doctor career, because the tasks change as you progress, and if you learn what clues to look for, you can actually figure out what disease the patient has without having to run a bunch of tests. The Detective is pretty repetitive. I don't play with that one much. The retail system is also a perk. You even get a new baking skill so that you can run a bakery.
Horse Ranch-
If your sim owns a horse, this pack provides immersive game play and I enjoy it. The rustic, wild west themed build buy is also a huge plus. Unfortunately, for your sims who can't or won't start a horse ranch, there's not much for them to do. There's no game play in this pack that a sim can just dabble in as a change of pace. You're either running a ranch/nectary as your job, or you don't engage with it. Kind of like how, if you aren't playing a vampire, you don't engage with the content of the Vampires pack. I'd say wait for a sale for this one.