I have a PowerCore PCI / Element card, is PowerCore 2 (and higher) compatible with it ?
In short: yes.
What you get:
With PowerCore PCI / Element running PowerCore driver version 2 (and higher), you get the benefit on newer improved drivers and more efficient CPU and plug-in handling, in addition to the new GUI design.
What you don't get:
20 hours of demo time for each optional plug-in. Why not
The above only works on 2nd generation PowerCores (all except PCI and Element).