Cherry MX Red and Gateron G Pro Red are very similar linear switches with smooth actuation all the way through the keystroke, suitable for typing or gaming. The Gateron switches are a bit more lightweight and have a shorter pre-travel distance, making them better for fast-paced gaming.
Outemu Red and Gateron G Pro Red switches are extremely similar linear switches with smooth actuation all the way through the keypress and short pre-travel. Both switches are well-suited for typing or gaming. The Gateron switches are a bit lighter, but this difference isn't significant, and most people likely won't feel the difference.
Gateron G Pro Black and Gateron G Pro Red are linear switches with smooth actuation all the way through the keypress. The G Pro Black switches are a little heavier-feeling and have a much longer pre-travel distance.
Gateron G Pro Red and Kailh Box Red V2 are linear switches with smooth actuation throughout the entire length of travel. Both switches come pre-lubed from the factory and have excellent smoothness out of the box. The Kailh switches are a bit more stable due to their dust-proof stem with perimeter design.