I am not happy with my Asus P4C800 Deluxe (bios 1006).
Asus has no FreeBSD gigabit drivers (3com 940), no stock Linux drivers (have to manually install ones from ASUS's ftp site), no DOS NDIS 2 drivers (so no Ghost or PowerQuest Drive Image action), no sound drivers under FreeBSD OR Linux (I tried every supported sound driver in FreeBSD 5.0 and in Linux 2.4.20 kernel), SMBus sensors busted (lm_sensors, chm, and mbmon all either fail or give bogus information, eg, cpu at 255 o C), you have to bring your own USB connectors, 1384 connectors, Serial ATA, etc.
I am NOT a happy owner at the moment because of the DOS NDIS 2 missing drivers. I tried getting drivers from 3com, Asus, Broadcom (part of the 3com chip is Broadcom), Marvell (the other part; the Yukon chip inside the 3com is from Marvell) to no avail. I hex edited Broadcom's b57.dos driver to add support for the 3com PCI ids (0x10b7/0x1700) and it probes but gets the Mac address wrong and locks the machine. I tried the Compaq and IBM "Broadcom" drivers also.
I do have a ATI 9700 Pro with a -10 rev, I do not over clock, it does work perfectly find under Win2K and gives me 4660 score on 3dmark03 with a 2.4ghz cpu.