Never heard of that before, but Modify springs are predictable and consistant from my experiences, and I've played around with every type of spring there is, and for the price and sponginess......... I always recommend the Modify springs because there are no surprises. And the Modify parts are hard to beat for quality for the price you pay. My opinion as well, but I've had all kinds of issues with expensive brand name parts, yet none with Modify. Maybe just a tolerance issue among brand names.

Wrong there.

It depends on the spring strength, please make sure you know the information you're giving others is correct before you give it out.

Where do you get this idea? That's 100% false.

I'm partial to Prometheus springs myself. I find them very consistent. Have them in a few of my guns now and found that my velocities are very consistent compared to both stock or aftermarket springs that were in the guns before. Every time I've thrown in an MS110SP into a gun, it's always given be between 350-360 fps (depending on barrel length) + or - 5 fps.

prom M120 here gives me +-1FPS on a buddy's MP5 lol It's scary cosistant

Even though the modify spring is also a JG/Echo1 Spring?

Check out The Airsoft GI Site, when you browse the Modify springs it actually says Modify/JG, Echo 1 in the item description. I just assumed it was true as they are a large vendor for parts.

I've actually decided on a Promethius MS90 spring, that in conjunction with the high grade internals from the KWA gearbox and the Madbull 6.03mm inner barrel should be in the 340-350 range.