I’ve had my Aivia Osmium for two days so far. It’s quite a bit smaller than the corsair width-wise, but that’s to be expected. It has the macro keys across the top and not on the side like the corsair. Although it’s using the same switches, the action and sound is a bit different. Much louder than the corsair (but not clackety, the cherry mx reds are non-clackety mechanical keys). Although apparently plastic, this keyboard is fairly heavy, and it has nice risers - even has smaller risers at the bottom end of the keyboard for stability if you keep the wrist rest attached.
Inside the box, there are 4 extra keytops included (and a key puller), but they have different glyphs on them. Like a lightning bolt, a shield, and two others that I forget right now. I suppose you can replace whatever keys you like with them.
On the right hand side of the keyboard, where the windows button would normally be, is an Fn key. I imagine this is for accessing the media control keys which are doubled on the F1 through F4 keys. Those are the only twin function keys that are on this keyboard, so it seems a waste to have a whole Fn key just for that. Next to the Fn key, where the windows context button would normally be, is a “Win lock” key. This button disables the left windows key. It’s a bit annoying, as out of habit I press right-winkey+L to lock my screen when getting up from my desk… only to have it fail, and then fail again when I press the now disabled LEFT windows key+L to try lock the screen, only to realize my mistake, press win lock again and do the left win key thing again. Sigh. I’ll get used to it eventually I suppose.
There are 5 macro keys across the very top left of the keyboard, for a total of 25 possible macro keys. You can configure 5 profiles, and switch between them by pressing the Aivia logo on the top right of the keyboard. Each profile has a different colour associated with it, so the logo changes colour depending on what profile you currently have enabled. It’s cute. The rest of the keyboard is backlit with blue LEDs, the brightness is controlled by the left roller just to the right of the macro keys. There are quite a lot of brightness variations, unlike the corsair which had 3 and off. If you press the roller, it switches the backlight off. The right hand roller is volume - pressing it mutes.
The cable is pretty thick, has a nice braided material cover, and it ends off in two USB plugs, and two 3.5" stereo plugs. One USB plug is USB2, for the keyboard itself, and the other one - blue - is a USB3 extension plug that is purely for the USB3 port on the right hand side of the keyboard. This is purely for convenience. There is also a USB2 port on the back side of the keyboard, inline with the numlock indicator. The 3.5" plugs are for extending your speaker & mic ports to the side of your keyboard. All the plugs are gold plated and have individual plastic covers.
So far I’m liking the keyboard, although it has taken me a few tries to get the keyboard in exactly the right spot, so I don’t keep offsetting my keypresses when I blindly reach for it. 
