Subdomain or subfolder, which is better for passing PR and other attribs

Hi,
I have a PR6 site and it's growing. recently i thought to launch a web hosting reviews section in it.
I am confused which one is better, shall i use a new subdomain on it or installing wordpress on subfolder will be better.
I meant
like or which will be better.
with latest PR update i saw that all my inner pr 0(n/a) pages that i had created within last 10 days are now pr4

Any suggestions plz?

Thanks

Folder without a doubt. Once you create a new subdomain you lose any juice in the metrics that have to do with the domain, authority being probably the most important.