I have all three of the DAR's, .177, .22 & .25. I have had all of them empty on me but it was easy to find the issue and fix it in each case. The poppet usually needs to be burnished to keep a good seal over time but since the gun is SUPER easy to break down and work on, a person that likes tinkering (me) can make them work.
I did have to exchange my first one due to a regulator issue and I am working on my .177 due to horrible accuracy. I was sent a couple barrels to try and so far, the accuracy is coming around.
I do have issues with hammer bounce after I modified the hammer spring on the .177 (lower fps) but that is my doing.
Good luck!