Basically intel only restricts some oc and raid features to certain chipsets. For oc support you should buy the z chips, if you want to be able to use a ssd as cache for a normal hd you need something with 7 at the end (not 5), but that seems to be a windows only thing. You can definitly use intel's (software) raid with mdadm on Linux as well (you don't need dmraid which has got no direct support for gpt partition tables - you see gpt partitions only when you manually call partprobe). There are more diffences in the number of sata 6 ports (1 or 2), native support for pci (does not really matter, if needed you get a pci-e to pci bridge on a board), amt support only for q boards. And even the number of usb 2 ports can be different. Just take a look there:
None of those changes affects the Linux compatibilty or stock speed of a cpu. If you don't need sata 6 (or native usb 3.0) you can use the older h61 chipset as well. If you get a cheap 2nd hand board there is no reason to buy a new one as long you have got the latest bios on it with Ivy Bridge support. Just some vendors do not provide updates for every board. MSI seems to be a bad example in that case...
running debian sid in a gigabyte z77mx-d3h, which i choose as to having less non-z77 features as possible (bad experience with asus feature ridden boards causing *way* more power drain than necessary)
usb, sata, etc all works.
fan control is huge no.
temp sensors seems right.
cpu freq scalling with a i5-3570K is wild. most bios can set the cpu to a specific multiplier, and/or to multiplier based on how many cores are under load. Then you add linux cpu governor on top of that... the result is a 3.4ghz cpu, with bios limit set as high as 4.5ghz, but stuck at 1.6~3.0ghz at all times under linux (even when compiling). But I don't think this is related to z77 but to the core itself.
most important to me is that nouveau supports the HD4000 just fine so far. performance runs circles on my old discrete 7300GT with the awful proprietary drivers. but again, irrelevant for a z77 or otherwise.
btw, unlocked intel cores for overclocking are the "K" ones, it was said differently above.
I was searchin info on ubuntu compatible motherboard+processor because I was planning to get a Gigabyte GA-Z77N-WiFi motherboard which has Z77 chipset + i7 3770 and I was not sure if I could run ubuntu on it. So I can get the stuff and use it with ubuntu 12.04 right?