Many threads on this, and much is just speculation, although the beta gives an idea. Check that out if you want a clue now. I see no point in playing a guessing game right now.
I don't have concerns about the ones you mentioned, but on the boot time, I don't think you will ever see much of a change there. This has been explained before, but the PB reloads kernels each time it re-starts, this due to security reasons, as was explained to me by our IT after his PB orientation. I've read this elsewhere also. If I'm incorrect, please let me know. That being the case, it's fine by me as I rarely even turn mine off or re-start it.
