I am currently running a NGR BOV and love it. I am currently running 10 psi due to break in process but I am loving the way the NGR performs and sounds.
For those of you that are not familiar with the NGR BOV's, they look the same as the Greddy type S but have a better, redesigned diaphragm.
These perform and sound better for a cheaper price tag!!! If you are currently running a Greddy or a ebay knock off Greddy BOV, I would recommend to atleast get your hands on a NGR diaphragm and install it into your current BOV. You will be surprised on how much better your car will perform.
Here is their site if you are interested in a NGR BOV
---$5--- - NGR - NEXT GENERATION RACING - HOME
Here is a picture of the difference in diaphragms, so you can tell if you have a NGR or not