Okay, I've changed my mind.
Sijom, that's exactly what I like about him. If we were getting JUST Spider-Man, I'd agree with you, but I think putting him an a de-facto Avengers joint... his age is what really makes him stand out in a crowd.
OMG THEY'RE REALLY DOING IT
Spider-Man, for me, was the only disappointing thing about this trailer. I love the character, yes, but I'm getting really tired of him as a teenager. A more mature version of him would be nice for a change, especially in the context of these movies where almost everyone is an adult over 30. Hearing a kid's voice at the end of this trailer felt really out of place.
I'm a fan of oldschool Peter who's 25 or so and married to MJ, but those days are gone.