I would say get both of them if possible but if not , I would go with University because you can send a sim to uni even as an adult or elder. Also, you can sit on skill classes any time for a fee. That being said, none of my sims graduated uni. I like the pack for the other things, roommates, robots, ping pong, kegs, cafeteria and food stands that work nicely with the community space lots from Eco Lifestyle, the world.
From Highschool years I like the world with the amusement park, the different bedroom furniture, the EZ window, the ivy ladders, the photobooth, the cafeteria and bobba shop, clothes stand that again work nicely with the community space lots from Eco Lifestyle. Though I prefer the uni cafeteria cause it has nicer food options. The highschool lot is huge but you can use it to create skilling spaces for the sims and all sims can hang out there outside of school hours. It also has lots of festive type furniture and decorations that can be used for weddings, parties and such.
crocobauraThank you for this! It's likely I will get both eventually, just thinking "what's next". I love the idea of university for elders! That hadn't occurred to me yet. Your comparison to Eco Lifestyle Buy Mode also helps (that was the reason I bought Eco Lifestyle).
I'm not sure how much I'd use the Thriftea Lot Type in High School Years, but I do love a Lot Type!
