A "High Speed" material is classified as fulfilling the following 3 criteria at a set printing temperature:

Flow: It can be extruded consistently at 24mm3/s. (equivalent to 300mm/s at 0.2mm layer height with a 0.4mm nozzle)

Form: At 24mm3/s, it has similar surface quality, overhangs, and bridging as if printing at lower speed.

Function: At 24mm3/s, it has least 80% of its overall mechanical properties as if printing at lower speed. (layer adhesion, tensile strength and impact strength)

By those criteria, Coex filament are considered "High Speed"

The Marketing Maze:

"High speed" filament is often a marketing term. Here's why:

Unrealistic Claims: Advertisements boasting "10x faster prints!" are misleading. Print time reductions are often dependant on your specific setup.

It may contain additives: Additives can adversely effect your print.  Finishing a print in record time means nothing if it doesn't have the properties you were looking for.

Focus on the Wrong Metric: Speed isn't everything. Print quality suffers at breakneck speeds. You might end up with weak, stringy prints.

The Spool on Speed:

Here's the thing: filaments can affect printing speed, but not magically. Print speed is a complex dance between factors like filament properties, your printer's capabilities, and slicer settings.

Temperature Matters: Different filaments have different melt points.  High Speed Filaments often just have a lower melting point. High speed printer manufacturers will often suggest you increase hotend temps to allow full melt before depositing the material.

Printer Power: Your printer's hotend and mechanics also play a big role. A basic printer might struggle to keep up with super-fast extrusion.

Slicer Savvy: Slicer software controls how the filament is laid down. Optimizing these settings can squeeze out more speed from any filament.

So, do I need "High Speed" Filament?

In short, no.  Many filament are inherently "High Speed".  And there are better ways to boost your printing speed than paying for a marketing term:

Upgrade Your Slicer Settings: Learn how to optimize slicer settings for speed without sacrificing quality.

Calibrate Your Printer: A well-calibrated printer runs smoother and faster.

Increase your hotend temperature: No matter what material you choose, it has a melting temperature. High Speed Filament often just have a lower melt point.
Invest in Printer Upgrades: Consider a hotend designed for high-flow printing or do your homework and choose a new printer that will suit your specific needs and is already capable of high speed printing.

The Takeaway:

If these filaments offer slightly better flow properties, you have to ask yourself why.  What is it really made of, or what is added that increases the flow dynamics?  A lower melting temperature may be good for printing, but the printed part may suffer. It may deform at lower temperatures or be brittle and easily break.  With some settings tweaks, you can print at high speeds without compromising quality!