Barrapunto

Soy al que has quoteado.

Mania de que? No lo digo yo, lo dice google:

Use Native Methods

When processing strings, don't hesitate to use specialty methods like String.indexOf(), String.lastIndexOf(), and their cousins. These are typically implemented in C/C++ code that easily runs 10-100x faster than doing the same thing in a Java loop.

The flip side of that advice is that calling punching through to a native method is more expensive than calling an interpreted method. Don't use native methods for trivial computation, if you can avoid it.

http://code.google.com/android/toolbox/performance .html [google.com]

Si conoces el tamaño de los elementos, para un string en C++, el caracter x de la cadena es desplazar x*tamaño un puntero. Si en java utilizas un bucle por cojones será mas lento.