9E is S3 on their own metal (like any other regional), S3B1 on DL mainline and any regional that's not Skywest/ExpressJet, and S3C on SkyWest/Expressjet. It really doesn't help a ton considering we can really only bump other regionals and DGS employees (but not DGS supervisors/managers, who fly at mainline priority).
Another thing that I thought was interesting was that on Delta Connection flights not operated by Endeavor (i.e. Compass, GoJet, etc.), the jumpseat is first-come, first-serve for anybody. I found this out the hard way on my very first nonrev trip, when I was trying to go GRB-MSP on a SkyWest flight. Because a JetBlue dispatcher listed before me, he got the jumpseat ahead of me. This is different than the AAG way where it goes pilots/dx on their metal, then AA/MQ/OH/PT jumpseaters listed as D2, then any other airline jumpseaters. Luckily, my friend in GRB was nice enough to drive me down to ATW, where I got the jumpseat on another OO flight back to MSP.
The best thing about 9E's benefits is being able to bump anybody out of the jumpseat on mainline who isn't a mainline employee (or FAA, etc.).