I don't like TS4 teens because they lack any distinctive features. I'm someone who takes tons of screenshots so I pretty often play with "headlineeffects off". This means I don't see the info screen above sims' heads which shows their name and age and let me just say: if the game didn't automatically block romantic interactions between teens & YA's my extremely flirty celeb would be a criminal now. Cuz I sure as heck couldn't tell they were teens by just looking at or listening to them. A few premade teens are the exceptions since attention has been paid to their overall style which has that "teenager vibe" but the randomly generated townies are a completely different story.
I now use a mod which makes teens a bit shorter. I don't care if it's "realistic" for them to be as tall as young adults. I grew sick of the fact there's nothing distinctive about teenagers while in previous games (and IRL) you can immediately tell them apart.