I've had zero problems with the 0804 BIOS. Having said that though, I suppose it's possible that different BIOS versions work better with different hardware configurations, so, if you're not having any issues with the earlier BIOS version, it might be a good idea to stick with it? Personally, I always update any board I get with the latest (non-beta) BIOS available. I've never had any problems yet.
I'd have to say that the P5B Deluxe is one of the best boards I've ever used. The only problem I've have with it is the lack of dividers for RAM. I'd like to be able to have the option to run my RAM at a lower frequency than the CPU FSB, but with this board, it appears that the lowest divider is 1:1 .