You'll Miss the API (Score 2, Informative)

First off, you're going to miss the Java API. I just spent the last semester in your predicament. I have a strong Java background, but I was forced to TA an intro to C++ class. I found that our text "C++ Effective Object Oriented Software Construction" by Kayshav Dattatri was a very good intro to C++ if you've got a Java background. He tends to make comparisions to Eiffel or Smalltalk, but Java comes into the picture often (and its pretty close to Smalltalk in a number of ways).

Also check out www.cppreference.com. I have found it to be significantly more useful than the STL reference at SGI.

To paraprhase Mark Twain, the rumors of the performance of C++ have been greatly exagerated. The advantage you get from cross platform compatibility and a fantastic API far outweigh a minor performance hit.