Ok, I've played with a number of disks, and BTB is showing on all of the callibration ones (I didn't check any early Sony-release easter egg callibration, since they clipped BTB anyways). No question about it. Subjectively, the color looks even better to me, but I wil wait for Sspears or Kris Dearing or someone who can do objectivce chroma measurements before I believe it.
Interactivity is marginally faster, especially FF and RW. Most important to me (and almost unbelievable to me) it fixed my problem with the SW out. The subwoofer out is very quiet (as is well documented) but before this firmware my SW audio out did not output anything. Now it does, and I am stoked. had to test a dozen BD's with uncompressed audio...I love it. When the Panny gets DTS-MA and TrueHD decoding it'll be the perfect player.