Based on the links your already provided, your wages aren't 15-25% lower than other major airlines. The DAL FAs just received a pay increase with the merger, so, the DAL FA rates aren't that far off from the others when you consider DAL just exited bankruptcy.
The bigger question you should ask yourself is, why are the NWA FAs who have union represtation, not that much better off, if any, than their DAL sisters?
My prediction ....
Based on the not-so-friendly actions already taken by the NWA FA union regarding DAL management, DAL FAs will unionize, the friendly culture at DAL dies, the union won't police itself and will allow substandard performance from the FAs all the while saying that they deserve more, and we see a FA strike within 10 years.
-Fatty