Pohnpei live rock

to tell you the truth, live rock is live rock. it doesnt matter where the heck it comes from. some rock has more coraline or hitchickers, but that usualy doesnt depend on where the rock comes form, but how efficiently it is collected and shipped.
if it looks good to you, get it, if not, dont

yeah, the different "kinds" of liverock is basically just the area that it was collected in.. now i'm not sure, so don't take my word for it, but it may have different "critters" that, say, fiji rock doesn't have, just because it may be from a different part of the world... in fact, i'm probably wrong because i'm somewhat new to saltwater aquariums, so my advice it kind of sorry...oh well...

I'm sure "Pohnpei" live rock seems and looks like all the rest. Check out this map:

http://worldatlas.com/webimage/countrys/oceania/fm.htm

If you look at the map on the right, you may recognize the different places that LFS sell their live rock from...

Tonga, Fiji Islands, Vanuatu, Marshall Islands, Ponape (Pohnpei), etc. As you can see, they're all relatively close to each other. I highly doubt there is any significant differences with the hitchhikers. If there are any differences at all, I would imagine them to be small or unnoticeable.

If you check out some places online you'll find some different kinds of rock for a lot cheaper than $6.99/lb. I just ordered some Tonga (Eva) live rock myself.

Hope this helps.