classic JVM vs J9 JVM

what is the advantage to running the new ( V5R4 ) 32 bit J9 JVM on the i5?

J9 JVM is PASE resident. Just like PHP.  Which means calling into a
Java method from RPG requires a tags active -> inactive thunk.  That
has to be slow.

The 32 bit J9 JVM has a 4GB memory limit. That is 4GB of memory per
process, but there are processes that run on the system, like
websphere web server, which can use more than 4GB of Java managed
memory.

The classic 64 bit JVM, the one iSeries IBM had been touting as the
fastest, most scalable JVM on the market, will not be available after
V5R5?

After V5R5, only PASE Java will be supported?

V5R5 will have a 64 bit version of the J9, PASE resident, JVM. Does
that mean the tags inactive thunk that occurs when calling from ILE
code into PASE will no longer apply, will be mitigated?

-Steve