That's all well and good, but I personally have no use for those. I've used the calculator button a few times when it's been available (though I typically just do "Win+R, calc, ENTER" since those keys are far from commonplace nowadays), but I generally just use Win+1 for the browser and personal email, Win+2 for Explorer, and Win+3 for my work e-mail (on my SP3 and my work laptop). Those buttons are also generally useless outside of Windows, so I don't really feel all that motivated to get used to them if they do exist.
I use the media keys all the time on my G710+, so it's kind of a pain in the ass when I end up with a keyboard that doesn't have them. It definitely doesn't help that every keyboard has their own idea of which buttons should be media keys. On my WASD keyboard it's Fn+Ins/Home/PgUp/Del/End/PgDn. On my laptop it's Fn with the arrow keys (the volume controls are F10/F11/F12). My Apple keyboard has all of them on F7-F12. Three different keyboards, three drastically different layouts.
You still have to contend with muscle memory with dedicated media keys, especially if you switch between keyboards often enough, but at least they stand out like a sore thumb, especially if they're backlit. With chorded media keys I always have to look around and be like, "Okay, where's the Fn key? Okay, cool. Now where are the media buttons?" during which time I could have already manually changed the song.
Oh yeah, I forgot to mention that. Those three keyboards also have the Fn key in a different place. It's between left Ctrl and Super on my laptop, between right Super and Ctrl on my WASD, and where the Insert key normally is on my wired Apple keyboard with numeric keypad. To add in some more fun and excitement on my other systems, it's to the left of left Ctrl on my MacBook and wireless Apple keyboard, where right Ctrl would normally be on my Surface Pro 3 Type Cover.
I think you can see why I'm annoyed.
Oh, right! The icing on the cake. My work laptop is a Precision M4600--a professional mobile workstation. You'd expect a modern $2500 high-end business laptop to put productivity first and skip some of the niceties that the home models have. I mean, media keys belong on Inspirons, not Precisions, right? Wrong. The Precision M4600 has dedicated media keys. Inspirons do not. What the actual fuck.
Ahem. Yeah.
And yeah, the backlit keyboards that I do have all have plain white lighting. I don't really need the backlighting to find my place, but I wouldn't mind having one with RGB lights just for the bling factor.