Boy does this article sound like it’s written by someone who has zero experience using 3D Printers.
While 250mm / s is a good speed, it’s important to realize that that doesn’t mean that it prints faster than a machine set to max at 50mm / s because both of those numbers describe maximums; The printer head will accelerate and decellerate, so in reality unless you’re printing something long and mostly flat, your printer will rarely actually get to those speeds.
This printer is also very overpriced. If you’re getting it for $ 450 (sold out already), it’s probably fine, but 759 is crazy. For that amount of money you can get an official Prusa i3 kit which is going to come with much better support and is a battle-tested design.