Button, button, what are the buttons?
Aside from the analog part, the particulars of the MK850 will sound familiar: RGB lighting, a full-size layout, multiple dedicated media buttons, a bank of extra macro keys, a metallic top plate, and a detachable wrist rest. Etcetera. Let's have a look at how Cooler Master laid out the MK850 and implemented analog controls.
First impression: Wow, that's a lot of keyboard. I suppose I'm not sure what I expected, but the MK850 is...horizontally generous.
There's a lot of extra stuff along the top of the keyboard, too. There are two rollers up there, one to control backlighting brightness and one for volume. Next to those are five additional buttons, four of which are media playback controls, and one that toggles the backlighting on or off. This top row feels both like a design afterthought and a thin excuse to put CM's new dual roller controls on something. (You'll find them on the upcoming Cooler Master ControlPad, too. Not for nothing, that device is loaded with Aimpad technology, as well.)
Initially, I had a similarly dim impression of the extra M keys and geez, three more buttons on the upper right corner of the MK850, above the numpad. I'm not sure I've ever seen a keyboard with this many keys, buttons, and rollers, and I generally detest extra googahs that are there for no good reason. But it didn't take long to see that the M keys and those three buttons exist to give you better analog controls.
The first of the three buttons toggles Aimpad on or off, and the other two let you dial the "sensitivity" of the analog input up or down. You likely won't be touching these buttons much. You don't need to turn Aimpad off to use regular keyboard input, and in practice I found that using the sensitivity +/- buttons within a game creates buggy problems.
This is the minorest of quibbles, but I think I would actually prefer the on/off toggle to be a two-key press instead of these twin buttons. Same goes for the sensitivity +/- buttons. I know, I know, why two keys instead of the one? Well, you just don't need to use those buttons all that often. And when you do use them, they're interruptive anyway, so why not make them all some variation on "Fn + [something]" and skip the unnecessary burden and clutter of creating dedicated buttons?
That whole vertical row of M keys, by contrast, offers important functionality as it pertains to Aimpad, and you'll be glad to have them available with a single keypress. Reflecting the Aimpad R5 prototype, there are multiple preset modes you can use for different games.
That includes a "Normal Keyboard Mode" that uses no analog sensing. So if you just want to use the keyboard normally, tap M1. You'll need it if, for example, you want to type into in-game chat; when engaged in analog mode, the analog keys don't produce letters. So you would open chat, tap M1 to enter Normal Keyboard Mode, type what you want to say, and then tap another M key to enter the analog mode you want. Technically, Normal Keyboard Mode / M1 is part of Aimpad, so entering this mode is not the same as turning Aimpad off. (Sometimes, you may need to kill Aimpad in the case of a bug or other oddity. For that you need the right-side toggle button.)
It's important to note here that only eight keys on the MK850—QWERASDF—are capable of analog input. I'm of two minds about this. Partly, it's a big letdown. Just those eight? Why not the whole friggin' keyboard, like Wooting has? But if we're being honest about the true usefulness of analog input, it's really all about control and movement in games (and potentially some professional productivity applications). That being the case, do you need more than eight analog keys? Sometimes, yes; I wish, for example, that at least the arrow keys were similarly appointed, because I like to use them for vehicles instead of the mouse.
The eight-key-only setup, though, is for the most part an acceptable capitulation to practical needs. The cost and complexity of making the whole keyboard analog may have been just a little too much, but also a mite unnecessary.
Analog aside, the MK850 offers tons of onboard controls. Without software, you can enable up to four profiles, get creative with the backlighting, and go nuts with macros. It's also worth noting that although the MK850 is in my humble opinion sort of ungainly, its brushed-metal top plate design is fetching. I also like that Cooler Master resisted the urge to go full gamer and instead employed an attractive keycap font. (If only the legends and sublegends were evenly lit.)