One of my friends once made a very good observation about rookie NBA bigs.
"I can tell as soon as they step on the floor if they're going to be good or not. If they're 7 feet tall and they're not an oaf then they'll be good. Araujo won't be good."
It makes a lot of sense. There just aren't that many 7 footers in this world. Well coordinated 7 footers are even rarer.
Valanciunas I like a lot because he's got really good hand eye coordination, and he's a genuine athlete (and he's 7 feet tall).
He's taking his game in the right direction to be a center that excels at rebounding and shot blocking. His offense isn't terrible, either, because he's got really nice hands around the rim and he can hit his free throws.
Also, he's shown rapid improvement in his skill set and physique, which speaks to a good competitive drive and work ethic.
For what I look for in a center prospect he checks all the boxes.
The only thing I worry about with him is how long it will take for him to be a solid contributor at the NBA level.