DaSilva wrote:How should I flash it? With the ASUS utility under windows or DOS?
Last 4 times I used ASUS utility on Windows (XP) without problems. Just make sure that you close all the weird programs (antivirus, firewall, speedfan/mbm/cpuidle and such) and that you have a stable system.
Anyway remember that the 'DOS' flasher is already included on the bios, so if you copy a bios rom file to a formatted floppy disk and press the required key on the bios splash screen (F2? I don't remember now) the Award utility will pop up and let you load the rom from the floppy

I think that this utility is more stable than Windows one, but it requires a floppy drive.
By the way, I would tell anybody flashing their bios, to have the computer connected to an UPS with charged battery: Murphy's laws say that the chance of having a black-out is never higher than when you are updating firmware.
DaSilva wrote:Should I backup all files on both HDDs
Having a backup is never a bad idea

DaSilva wrote:What is the difference between Trats and Uber version?
They have been 'modded' by different guys, but they are not so different: both have options that where hidden on official bios (mainly overclocking-related options and such) and some tweaks (i.e. you have a Trats bios with CPC off / T2 that may help with some memory modules failing at high frecuencies). But I think both have the same tweaks -aside from the CPC off on the special Trats bios version-.