I have to say I am also less than impressed with AII too
I bought the 4-pack of RD-22 from the Rebreather World store which had to be replaced last year.
Now one from the replacement batch has just failed
( awaiting response from Rebreather World store )
I think if anymore fail, I will be going back to Teledynes from Vandagraph, which performed flawlessly for me.