No dog in this fight but some quick thoughts. To the senior regional guys, being junior on a decent list like DAL's is far better than being senior at ASA, Xjet, or wherever. Probably does not hold true at CAL, US, UA but at a decent place to work like DAL, no comparo. I'm junior at Blue on the slave jet and while I'm no lover of mgmt here my QOL is better in numerous ways; hotel quality, CPO quality, Scheduling, you name it... and those things are mostly better at DAL than they are here.
As to the E-jet series, it's almost a mainline jet but you guys absolutely want it on the property. It won't carry much belly cargo but the 190 will do 100 pax on a max-range flight with 2 alternates. Pax love it when it works (dispatch reliability has been suffering lately here at Blue). I enjoy flying it when it works but personally can't wait to go fly Fifi (much larger, quieter cockpit and I'd like to kill whoever designed Embraer's seats). The 190 is a better performer than the 170/175 due to the larger wing and would fill some nice niches for DL. Won't replace the 9 due to cargo issues, but can fly a lot farther in some markets where that's not such an issue. Regardless, good luck to both sides. More aircraft and jobs on the mainline property is a GOOD thing.