As such, C++, Java and C#, which constitute a significant chunk of OO programming, are probably better thought of as descended from Simula (and C).
There's a clearer lineage to the likes of Ruby and Objective-C, and to a lesser extent Javascript and Python.
I would definitely concur regarding looking into it, it definitely makes you think about things in a different way.
Whether or not it makes one a better programmer, I can't say. I only programmed professionally in it for a relatively brief time and it was a hugely frustrating experience. I was glad to get out of it.
In the sense that it made me understand that a programming environment has a big influence on how well a codebase can scale then, yes, I learnt loads. But that was because it really wasn't very good at scaling without an awful lot of TLC. I moved onto a Java application which was bliss by comparison (ironically, given its reputation for classpath hell etc).
This was some years ago mind so the state of the art of Smalltalk has, I'm sure, moved on.