Well, I got mine a day before I was going to play. I installed it, decided I should test it.
Got some air, threw in a few balls went outside, it worked flawlessly. Probably around 20 rnds through it? Put it away until the next day.
Went out to play the next day after conversing with my brother who I purchased one for as well on the installition of the little bugger. Was about to go on the field when my brother was test firing his A-5, and he stopped me and asked why the Cyclone wasn't feeding. I wasn't sure so I turned my grip on and fired a few rounds at the test sight. Shot, once, skipped two to three times and fired again. I wasn't sure, played with the velocity a bit, adjusted my reg, everything seemed fine. Took the Air off and dropped a few drops in my air line. I had recently cleaned my gun I knew everything was oiled, just wanted to make sure. Tried it again and pretty much the same thing happened.
I put my old banjo fittings on and she fired like a champ, not sure if I just got (two) bad QEV's or what the deal is, but it wasn't worth the time and money spent.
I would look elsewhere before purchasing one from here, or perhaps call and find out if there is technique to installing them and making them work? Your dollar, just here to help. Didn't work for me so it gets a 1.
"F.A.Q.=== My Cyclone wont feed after I install the QEV. The QEV can be adjusted for more flow. Unscrew the shorter (non barb) end of the QEV so you can see about half of the o-ring. This will allow the rubber bumper more room to move at lower pressures. Some A5s just don't like QEVs." - http://www.palmer-pursuit.com/a5qev.htm