The Siberia 800 is the successor to the H. Technically, however, it is the same. 800 is for several platforms (especially mobile phone compatible), P is for the PS and X for the XBox 360. I'll get the 800 and give you feedback
I have the Wireless H and it is definitely worth the money! I had also wondered about this and have to say it's simple: The 800 has been renamed Wireless H. The 800P comes with Bluetooth, but is not due until 2016. And the new Elite is supposed to get some new technology, but it's still unclear when the release is. Take the Wireless H ;)