An emphatic YES. High level runtimes break, behave oddly, or do things that you wouldn't expect. Understanding how the machine works (and by extension, how the virtual machine works) is key to understanding:

* Why your program behaves the way it does

* Why your performance profile looks the way it does

* Gives you the skills you need to debug inevitable problems in your high level tools.

I highly recommend Write Great Code: Understanding the Machine:

http://www.amazon.com/Write-Great-Code-Understanding-Machine...