This article is riddled with inaccuracies and mistakes.
For example the article states that higher resolution numbers are better. False! Did you ever actually touch a 3D printer? A 100-micron resolution printer is 4 times worse than one with 25-micron resolution. The article has it the wrong way round.
Secondly, cooling the nozzle at the end of a print isn't a feature of the printer, it's something added in the slicer under the end gcode. Literally every printer does that! An actual safety feature of the printer would be thermal runway protection, which I didn't see anywhere in the article. I'm not going to explain it here - the author can do his own research on the reprap or Marlin firmware website.
Lastly, for an article entitled "which 3D printer should you buy" it's sorely lacking references to actual 3D printers. A more accurate title for the content of the article would be "what type of 3D printer should you buy" - and the answer to that is, unless you have a dedicated room to handle the toxic resins/powders of SLA, DLP or SLS printers, the only printer you can realistically use next to a computer is an FDM (FFF) printer. The most popular one is the Creality Ender 3.