First time trying this type of spring, I swapped it into a JWK black linear and a black T1 and it worked pretty well. For the 63.5g linear it made its hard to describe but it's heavier and more snappy. For the 67g T1 it was amazing, I used the 80g spring and it was heavier, bigger bump, more snappy, felt so good ^-^. More tactile than all my other switches except for my Kailh Box Crystal Navy Blue switches which are clicky so they're kinda cheating lol.

These were exactly what my SP Stars needed, being dual stage and a longer spring meant I could go down to 62g instead of the stock short spring 65g and it felt exactly the same but 10x smoother

This spring is dope, I put 80gs in my black boba u4ts.

They increase the tactility of the down stroke slightly, and very noticeably increase the tactility of the up stroke. if you get these for feel you wont be disappointed. At 80g they are a bit heavier than 68g boba, but it's balanced well, and doesnt feel much heavier.

The upstroke or rebound is also faster, you can actually see the difference side by side. It makes the switch feel more responsive.

Sound wise it doesnt change the down stroke much but the up stroke is a bit louder which makes sense with the rebound speed.

It was worth the time it took with a precision flathead screw driver to pry open all 84 switches.

Feels unexpectedly heavier than one would expect. They do have faster return. If you’re used to 62g, 58g should be fine, and if you’re aiming for 65g, the 62g springs should be fine.