I cannot agree more than the fact Leo is the perfect actor choice for Cobb. Just watched it yesterday ^^. Leo dissapears behind Dominick Cobb caracter.
Since his first role in the beautiful movie "Titanic", he was to my eyes in young and cute adult for teenagers " Titanic", "Romeo and Juliet", "The Beach". And I couldn't appreciate his acting.
I had to wait "The Departed" to see a grown up Leo. More mature with more personnality. A real adult. Miles away from Jack in Titanic. And I began a fan of his works "Shutter Island", "Django Unchained" or "The Wolf of Wall Street".
Just a little dissapointed he won an Oscar for "The Revenant". He was better in other movies (as Calvin J. Candie for example)