I bought a valve for a 1# nitrous bottle from Nitrous Express (NX). It leaked from the beginning, emptying the bottle in a day.
I sent it back to NX and they sold me another one at a discount, though by the tiime I'd paid for shipping I could have just bought a new NOS valve for the same price. The guys at NX promised to return me my first valve but it "got lost" and that never happened.
Well the second valve leaked just like the first. I sent it back and asked for my money back. I was told that I would be given a credit but months have gone by and I never received it despite several emails.
Another board member has also had bad luck with NX equipment having had a valve go bad and a solenoid fail. He ended up rebuilding his entire system with NOS components.
This has been a bad experience all around and I'm out the price of two valves plus shipping with nothing to show for it except that its painful to sit down now.
Buyer beware!
Eric