Ok, I just wanna share my little story if anyone wants to try and exp in promies.
Last night I went in promy-dem with Sakhmet to farm some memories to make anima. After a while on the first floor, it got boring cause we were killing empties so fast. Jobs were me RNG/NIN and Sak WHM/BLM by the way. Even Goger, Barrage (with gun) for 531 dmg, half his life gone on the pull, easy 60 exp.
So we decide to take on the receptacle on the first floor, just the 2 of us. Easy. Got to the second in no time.
On this floor, everything was EM or T, with Gogers being IT. We could get exp chain #1 on a regular basis and #2 a couple of time. Exp was between 46 and 90, with one 115 on exp chain #2. So I guess if you were to duo there, exp could be decent per hour, but more people in the party, not worth it I think.
So after an hour or so there, we decide it's time to get out and we should do it with style! So we attacked the second receptacle. And defeated it! Now, I don't know if these increses in strenght like the empties from floor to floor, but it took more time and used that Seed ability more often.
So, it's possible to duo your way to the 3rd floor. For the 2nd receptacle, strategy was really easy. I use millitary gun and bullets by the way. First, kill the 3 strays (with the gun, it's a one-shot kill). Then shoot the Rec. but don't engage it. That way, when he pops a stray, just one-shot kill it on the spot. DON'T let the strays get to the whm. Receptacles always did the same thing, 3 strays then Empty Seed. So when you killed that 3rd stray, put your shadows up and fire at the Rec.
Whm kept Dia on the receptacle the whole time to prevent it from recovering. Use Barrage as soon as it's up and ws with TP you build off Strays. It takes a while to kill that Receptacle, but using that strategy, we got through it with more then half the whm mp left and I got in yellow twice only.
Once on the 3rd floor tho, we really had to log so we went for the Satiator. Ate us alive

. Everything there was VT or IT, but we did not try. My guess is if you go with a reduced party, i.e. 4 members, you can probably gett good exp. Chaining I am not so sure about that.
For exp, we both are 30 and 31 outside of promy, so all that have stated is probably the best exp you can get in there.
Don't know if that helps, but if you wanna exp, I suggest a duo on the 2nd floor or 4-5 people on the 3rd one. AoE will kill your chain tho, as stated by someone previously.