I was never aware the P30 files WEREN'T support in LR. I've been trying out LR the past week or so (could never get through the betas) and I am liking it quite a bit. It worked so seamlessly with the P30 IIQ S files, I thought it was officially supported.
And like James said, I am also noticing it holds more info in the high end and it also has a little more latitude to massage the files than C1. When I'm in C1 and find a shot that I blew a highlight that I need that a linear curve can't recover, I bring it into LR and that has been able to do the trick...
However, I have only had occasion to try this out on my 17" MBP on the road. When I return home, I'm sure I will be pissy that I can't merge the thing with a database on my main workstation (obviously this is not the case, just yet), but I know for someone like James who tethers on the road and works at home on his G4s that this would most likely be an issue. Though the idea of maintaining different databases and pointing them to new locations is not a horrible workaround, there really should be a robust way of merging from the getgo. I really hope Adobe gets around to it quickly.