Not really fast, but it is more balanced and less telegraphed.
Sports Science is an awful show, and using a guy who is an MMA fighter to show the difference refreshing like te kick and Thai kick is awful:
This is an example of a Muay Thai kick. Obviously, there are several variants, but they all keep the leg very loose and the power comes from pivoting the hips completely through the target.
This is an example of a Shotokan Karate kick. There are also several slight variants, but they all have a slight chamber and a good chunk of the power comes from the quads when snap the kick out of the chamber. It should come back and bring you into a stable stance.
Obviously Machida does a slight combo of the two, but it's much more Karate, and I'm not sure if he's really throwing a hybrid or if it's just not a picture perfect Karate kick and he's throwing it with power.
And people throw Karate kicks with shin all the time; the overall goal is to use the ball or instep, but if you're too close, you don't just withdraw the kick, you kick through with the shin.
Edit: and contrary to what one trolling hapkido artist will tell you, there is nothing like a Thai kick in any traditional japanese karate system.