When comparing HummingBoard Gate vs Onion - Omega 2, the Slant community recommends HummingBoard Gate for most people. In the question“What are the best single-board computers?” HummingBoard Gate is ranked 23rd while Onion - Omega 2 is ranked 44th. The most important reason people chose HummingBoard Gate is:
Since the HummingBoard Gate comes with different versions, including different CPU versions, it can also run the same software without any problem on any CPU regardless of the number of cores.
Specs
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Pros

Pro Same software runs on single to quad CPU without any problems
Since the HummingBoard Gate comes with different versions, including different CPU versions, it can also run the same software without any problem on any CPU regardless of the number of cores.
Pro Some models fit inside a Raspberry Pi case
HummingBoard-Pro and HummingBoard-Base fit inside a Raspberry Pi model B case (but be aware that many cases will block the IR).
Pro Extremely extendable
Hummingboard Gate has a native mikroBUS system which lets users attach any “click board” that’s compatible with MikroElektronika’s system. This way the board can be extended by adding motion sensors, wifi cards, physical buttons, temperature sensors, NFC or Bluetooth and much more.
Pro Can be used as a media streaming device
HummingBoard works really well with Kodi and can be turned into a media streaming device with ease.
Pro Selection of great operating systems
Hummingboard supports OpenELEC 5.0, GeexBox XBMC, Android and Debian officially, but it can also run ArchLinux, openSUSE and Fedora successfully.
Pro It's tiny
Pro It has lots of shields available, including Arduino shield
Cons
Con Pretty expensive
Starting at $70, prices can go up to $235 depending on the model and the components that users choose to add to the board. For these prices it's rather expensive relative to other single board computers.
Con No built-in Wifi for the cheapest version
The cheapest version of the Humingboard Gate doesn't have a built-in Wifi card. You can either buy it separately as an add-on or you can buy a more expensive version of the Humingboard Gate which has a built-in Wifi card.
Con Not breadboard compatible
The board does not have the standard 2.54 mm pin spacing.
Con Support issues
There have been long-lasting periods were everything grew stale, even when it was about fixing security issues etc. have given up on checking since it was frustrating.
Con Expensive
It has less than 256MB of RAM.
