This is a great valve for the following reasons:
1. It allows you to lower the operating pressure on your gun.
2. It makes the gun more gas efficient.
3. It make the velocity more consistent.
It's a lot more expensive than other valves, but I still think it is worth it. Note: you need to have other low pressure components (high flow reg, softer springs, front air chamber, high flow bolt, 98 size air chamber) to maximize this valve's potential.
Definitely worth the money to lower the operating pressure. I Highly recommend it.