upgrade receiver or sub

my next upgrade will be either upgrading my aperion 12in sub to the new outlaw sub, or upgrading my 970 to a new released outlaw pre pro which will handle TrueDolbyHD from my blu ray player (right now i can only get DD because the PS3 does not have 5.1 analog output)

which upgrade would offer the best imporvement?

Would upgrading sub be a big upgrade or sudble?

Well, the upgrade of the pre-pro will probably not happen until late 2007 or early 2008 (with 2008 being the more realistic date), so if you are planning to do an upgrade sooner than that I'd go with the sub. If you're not going to mess with either until early next year, I'd probably go with the 970 upgrade.