The Suomy S1-XR GP is significantly better for the track than the Nexx X.WST3. These two helmets are designed for different riding styles: the Suomy is a dedicated racing helmet, while the Nexx is a premium sport-touring helmet.

For track use, the Suomy S1-XR GP is the superior choice for several critical reasons:

1. Certification and Safety

• Suomy S1-XR GP: Carries the FIM Homologation (FRHPhe-01/02), which is the strictest safety standard required for professional racing (MotoGP, WSBK). It is built to withstand high-speed impacts and extreme track conditions.
• Nexx X.WST3: Certified to the ECE 22.06 and DOT standards. While very safe for the road, it does not have FIM homologation.

2. Field of Vision (FOV)

On the track, you spend much of your time in a “full tuck.”

• Suomy S1-XR GP: Features a massive 92° vertical field of vision, allowing you to see much further up the track when your head is down. Its 210° peripheral vision is also class-leading.
• Nexx X.WST3: Offers 85° of vertical vision. While good for street riding, it is less optimized for looking through the top of the eye-port in a racing crouch.

3. Weight and Aerodynamics

• Suomy S1-XR GP: Weighs approximately 1400g–1450g. It was developed with over three years of wind tunnel testing to be stable at triple-digit speeds, featuring a stabilized rear spoiler and a very low drag coefficient.
• Nexx X.WST3: Weighs around 1550g–1670g (depending on the shell version). It is noticeably heavier because it includes features like a drop-down sun visor and intercom housing, which add weight and are generally unnecessary on the track.

4. Track-Specific Features

Feature	Suomy S1-XR GP	Nexx X.WST3
Visor System	Racing Lock System (metal alloy)	Standard recoil system
Tear-offs	Ready (tear-off posts included)	Not standard
Hydration	Prepared for “Camel-bag” systems	Not prepared
Sun Visor	None (saves weight/complexity)	Integrated drop-down
Ventilation	7 intake ducts (maximized for high speed)	6 intakes (focused on comfort)

Verdict

• Choose the Suomy S1-XR GP if your primary focus is track days or competitive racing. It is lighter, more aerodynamic, and offers a better field of view for aggressive riding.
• Choose the Nexx X.WST3 if you want a high-end street helmet that can occasionally handle a track day but is mostly used for commuting, touring, and everyday sport riding.

Note: If you like the Nexx brand but want a true track helmet, look at the Nexx X.R3R, which is their FIM-homologated equivalent to the Suomy S1-XR GP.