Postgres on Windows: Performance hit?

Hi. Is there any problem running Postgres Server on Windows xpPro? Since it has to
go thru a Unix translator, does it incur a performance hit? If you have experience
with this, please report. Thank you.

Also, what is the minimum and recommended RAM requirements?

And, this is a 'funny' question. Can Postgres co-exist with Oracle on the same
Windows machine?
One more question (and I let you go); any problems running a client (Java) program
on the same machine as the server?
Ok, last question, any problems accessing an Oracle database with a Postgres
database simultaneously from the same Java program?

Thank you all
-Nat