i have one and its 10 times better than my previous one, which was x4 labs - and most other ones are the exact same as this, just boxed under a different brand like jes extender, size genetics etc - they are all the same thing. but they are a lot of bother to deal with everyday and not as easy to put on and adjust, which makes you not want to wear it because of the hassle.
the male edge is probably the best one out there. its light and snaps together - no annoying screws to tighten all the time.
if you are getting a traction device - get this one. definitely.
have been using it on and off for about half a year. straps haven't broken or worn down... and anyway i was supplied with a spare strap even though i got the standard edition one.
haven't measured if there are any gains, using it for a wicked right curve. i think it may have improved it a bit. but didn't take before and after photos. definitely gives you a bigger flaccid hang though.
will continue to use it. just need to use it more often (lazy bastard)
if you get one, i have a few good tips for it that you come to learn after experience.