Those boards are gigabyte designs manufactured using a bit lower quality components. Functional, but you shouldn't use them if you intend to upgrade your PC in the future because I have seen absolutely no BIOS support for these boards.
No they're not. There's an interesting story where it left bad taste amongst some people. Suffice to say that this is how most people do business where they work in a tier 1 brand and then get an investment/partner and then shift to a lower tier band bring in chinese relabeled trash in our country.
In my experience the hierarchy goes something like this:
low end: Biostar/MSI (also ECS and Foxconn if overclocking is not a concern)
low-mid range: MSI/Gigabyte/Asus
Mid-range: Biostar/ASRock/Gigabyte (Asus and MSI often have feature limitations at this price range)
Beyond mid-range any brand provides decent value for money.
You forgot where MARS board came from.
And you're wrong- again. Didn't I correct you about something else the last time??
Gigabyte makes really good low cost board and they're being it doing for so long. Gigabyte G31 ES2L, G41's counterpart, 790x (or something) UD2H, 880gma ud2h (which didn't really come here) and 880gm usb 3...and many more. They make pretty good mid end boards too. A lot of people have pushed G31 ES2L even with Q6600 and never had issues. There are people who still use it. There are times make a board which doesn't really stand out, but they make solid boards. I remember a lot of people back then used to tease gigabyte for colourful pcie slots and used to recommend other boards- back in P35/P45 days, when infact boards like DS3L were super good. Back then. IP35-e and pro were around. That's probably another reason why not many looked towards gigabyte. That changed over the months since...790G/Intel x58 days.
....and I am not the only one who will say this.
GD55/65 have issues more than 1 time where some issue or the other crops up. ASROCK was recently criticized for labeling a board with analog VRMs for digital VRMs- but they make good boards. But if you search around, ASROCK Extreme 6 has a particular issue when all the 4 slots maxed to 32GB has issues in most cases. GD80 series from msi is pretty decent but there are better boards, but haven't been following since AMD 8xx days.
Biostar? Its commonly known that initial rev versions are pretty okay to use but newer ones fail much MUCH quicker.
Asus has a share of making Great boards, decent boards and well...some are simply way too "premium" for most end users.
There have been times when we have so much choices- but there's zilch no good choice. No1 reviews Intel boards. But considering that lower tiers do some crap or the other- having a good stock board is the way to go if you can't afford to spend more money.
And out of all the companies, I would like to see MSI stepping up. They make good cards- reference and non reference. They should do the same for motherboards too. That's how Gigabyte is with VGA and motherboard is.