In practical terms, the Sanyo will probably give you as good or better blacks due to it's
Image AI. But this won't give you deeper blacks on every type of image; if you have darks and bright parts within the same frame the AI can't ratchet it down.
FWIW I've heard a lot of bad things about Sanyo's warranty service. And it sounds like the Panny isn't really designed to be used for long stretches at a time- there's a big stink over the Australian version having a provision where watching it for over 4 hours a day 3 times a week voids the warranty!

You can read about this in detail at AVSforum.
Both the Panny & Sanyo PJs are quieter than the Mit's. But the Mits isn't loud by any means, just not LCD quiet.
I've researched those three PJs myself. And I plan on ordering the Mitsubishi within the next couple weeks. The reviews are very good, the PJ is bright with good black levels. And having owned DLP PJs for about 5 years, I know RBE isn't an issue for me.