It's all a crapshoot, but most have been getting to ATL in their first AE (still a 4-6 month wait). However, with a solid year of hiring it's hard to predict how many 717/88/even 737 types will move to the bus above you. There's slight movement at the bottom with moves to DTW/SLC, but the top (even FOs) is very senior. I was hired in Sep and haven't moved up, but the bottom has from 30 spots below me. I had a commutable line in Feb (Dec/Jan reserve). With all the uncertainty I'd pick the plane you want, I've never regretted picking the 320. By the end of the year the category will really grow to prepare for the 321 arrivals in '16, too.