If I had 20K to spend right now, or if I magically, gradually save 20K over the next year or two, on my wishlist are things like:

-- Canon 1DX Mk II :). Sure, I do like the images out of Blackmagic, Red, Arri better (not sure about Sony). But if I ever need that sort of quality, I'll rent. The 1DX would be mainly just for fun. It's a do-everything workhorse without the ergonomics and workflow pain of many more expensive options. Price: $6,000.
-- I really like the Westcott DP and booklight kits, and find myself typing those keywords into eBay a lot, although there are DIY alternatives. (Need a booklight? Cover a screen with aluminium foil, blast it with worklights, and bounce through a bedsheet -- beautiful results. Learned this one from Matt Scott.) Price: $2000.
-- Miscellaneous light control. Scrims, flags, etc. Price: $3000.
-- Good old dedolight three-light kit. Don't need, but can't help but want. Price: $4500.
-- Some big soft lights. Not thinking Kino Flo so much as Jemballs or a Westcott 7' octobox. You can do amazing things, for photography as well as video, with just one bigass octobox. Price: $1000.
-- It's a couple of years old, but there's a 30ft crane made by Came-TV I'm eyeing off. Previously featured on NFS: http://nofilmschool.com/2014/02/came-tv-33-ft-camera-crane-review-neuman.... Price: $2500.
-- Would love some motion control. Don't have any. Got a small Edelkrone slider, but wouldn't mind a long Edelkrone slider + target + action modules. It's not the best motion control by a long shot; Kessler makes stuff that is a lot quieter with more features. But the simplicity of setup makes it better for run and gun; and it's surely good enough for 90% of shots anyway. Price: $2000.

Grand total: around US$21K brand new.

Another way this thing could be useful, although it's a very niche way: what if you wanted to adjust diffusion smoothly in the course of a take? How could you do it otherwise?

Shotgun mic is still useful on-camera in docs, because there's plenty of times when you're relying on on-camera audio. But I'd consider at least one lav set a necessity, and am sceptical a monitor is needed at all.

I don't know what the top software for reducing noise is, but Shane Hurlbut used Dark Energy: http://www.thehurlblog.com/cinematography-online-dark-energy-lightning-i...

Here's some articles:

http://nofilmschool.com/2014/10/neat-video-vs-denoiser-ii-which-plug-bet...

http://nofilmschool.com/2015/03/super-powerful-noise-reducer-dark-energy...

At the end of the day, it's more about what pushes your buttons, and less about objective technical qualities, like resolution and dynamic range. And what pushes your buttons might be a cheap camera, or might be an expensive camera, and might well vary from project to project. There was a recent American Cinematographer article about someone who still loves their DVX100 -- just the particular look it has.

Can Canon DSLRs make "amazing" images? Well, if you watch the video from those cameras, and they don't do it for you, there's not much else to say :). Don't buy a Canon DSLR then! If you look at Blackmagic videos, and there's a higher amazed to not amazed factor, then get one of those instead.

So, that's one way to answer your question. Some people love the look of Canon DSLRs. Some people think they're too soft. Some people, like Andrew Reid, think there is a magic in the 5DMk2 that was somehow lost in the Mk3 and in the EOS line of cameras. It's all very subjective.

But there's another obvious way to answer your question, which is that it's more about the user than the gear, and of course a skilled artist can produce an amazing image with any camera.

Well, here are some other options:

-- Shoot on a smartphone. Have you seen the recent NFS demonstrating that, when treated properly, and compressed for web, a smartphone isn't particularly different from a RED camera?
-- What about the older generation of cameras, like an HVX200? Ridiculously low-price used, and extremely flexible camera. Huge zoom range, built in NDs, XLR inputs, etc.
-- What about filmmaking on a GoPro?
-- What about getting an old super 8 camera and shooting on film? In many respects, the image will surpass digital cameras.