So GB mobo is better choice because the installation will be easier? In fact how hard is to install ML on Asrock? I personally prefer Asrock and the only reason I haven't bought the mobo is because I think I'll fail the installation :x I've read the tutorial about Asrock motherboards twice but I didn't get anything
PS - I'm sorry for my bad English :x
installation? no
ill try to explain it in an easy way, but one where you have enough info to make your own judgement.
there are 2 reasons why gigabyte
uefi boards are favoured; 1) they do not have a critical part of their bios locked 2) the dsdt in the bios is compatible with osx natively (remember this is the uefi boards, so gigabyte z77 etc, and now the older gb boards are getting uefi)
so lets break this down in relation to other brands (asus, asrock, msi)
1) there is a part of the uefi bioses which deals with cstate config. all mobo makers since last year (except gigabyte as they were using award bios) have left this part locked. when the appleintelcpupowermanagement kext tries to write to it, it cannot and kernel panics.
by modifying the bios to remove this lock, we no longer have this issue, and can boot with the native power managment kext without problem.
gigabyte uefi boards do not engage this lock from the factory.
2) the native dsdt of gigabyte uefi boards is known to work fine with osx. this means that sleep, wake up, usb, shutdown, restart etc all work without the need for modifying the dsdt.
this is also the case on other uefi boards, including asrock, msi and asus boards.
however, not all of the native dsdts on these other brands are equal. for example, one model of asus board might not need a modified dsdt, while another one might need a slight edit for sleep.
thing to note is that as uefi progresses, there has been less need for modifying the dsdt, eg. early asrock roms (such as from last year) needed dsdt modifications for sleep. with the latest asrock roms, this is no longer the case.
the most latest uefi roms seem to work great for all brands, including asrock, gigabyte, asus and msi.
in short, you cannot 'fail the installation' as long as the cpu and graphics card are fine.
the asrock z77 pro 4 or pro 3 uses realtek lan and audio, so thats fine.
you can obtain a modified bios from the link in this thread.
you will not need a modified dsdt for shutdown, restart, usb, boot up etc.
you
may need a dsdt edit for sleep, i simply can not say with 100% certainty as i have not seen your board used yet. however, from what i have seen on here, other asrock *77 boards and the 6series asrock boards using the latest uefi roms do sleep natively without any dsdt edits.