Many applicants are being given the choice between the two airframes. With the ERJ, you don't get Delta non-rev benefits (a big deal for some folks), and your two base choices are ORD and SFO.

If you want the ERJ/SFO, it's anyone's guess as to whether a new-hire can get it. They just put a bunch of new-hires in that slot, but from the transfer/ transition lists I can see, a bunch of guys are putting their bids in for that airframe and base.

On the CRJ, the junior bases are MSP and ORD, followed by DEN and COS at the moment. SEA, PDX, and SLC are the most senior. SFO, PHX, FAT, PSP, LAX, and IAH are all in the middle, seniority-wise, as far as I can tell. TUS is another base, but it's really small.