Never used the XC15, but I do own an XC10, which I believe is mostly the same.
I hate it for run and gun, but your mileage may vary. Depends partly on what you mean by "run and gun" (eg how fast are you gunning) and what you're comparing it to.
Reasons I hate it: the focus throw is too long. And there aren't the physical controls you have with a DSLR (for instance, just not as fast to adjust white balance, ISO, shutter). If you stay in the same camera mode, I think you basically have to dive through the touchscreen menu. There are ways to minimise the lack of physical controls problem by switching between different camera modes (I've seen a YouTube video about this); but still not as convenient/fast as a DSLR.
Ed, if you just mean "a slider can do a horizontal dolly-like shot, and so can a glidecam", then, sure, they're similar. But there's plenty of things that each can do that the other can't.
One big difference is this: sliders can allow very slow, very controlled movements. Not even talking any sort of motion control or timelapse. I could mount a 70-200 lens on my camera and do a 10 second shallow depth of field shot where the camera slides 5cm, simultaneously tilts upwards, and pulls focus to a different object. Try holding a glidecam steady and doing that. Even with a steadicam and a vest, where maybe a second person can pull focus, the movement isn't going to be as controlled as with a slider.
Yes, it is a better example! Haven't seen that before. Though I wish Martin also walked backwards, like the guys in the Shorewood Lip Dub (https://www.youtube.com/watch?v=T7TI-AJi2O8 -- backwards, and slow motion).
I think that's excellent advice, and not only for cinematography (as long as the camera work doesn't get in the way of the story). It's also excellent advice for filmmaking in general -- show the audience something new, give them access to, insight into something they haven't seen before (eg, an alien planet, the inner workings of the White House, the moral quandaries of war).
I guess this goes without saying, but Google for "realistic rubber knives".
Don't know if rubber knives come in pocketknife form, though.
Two similar effects:
-- OK GO's The One Moment: http://nofilmschool.com/2016/11/ok-go-the-one-moment-slow-motion-music-v... . The band members had to yell out gibberish at high speed that looked normal when slowed down.
-- Coldplay's Yellow. Chris Martin had to sing at double speed, so that he'd be singing in time to the song when it was slowed down, with everything else in slow motion: https://en.wikipedia.org/wiki/Yellow_(Coldplay_song)#Music_video