If you left as a Captain and/or have the time you will almost certainly come in as a direct entry Captain. Solid program as you will go through initial with a new hire class and essentially get re-typed. You'll get pay rate and 401k contribution based on years of service 121. That means you'll come in at up to 10 year pay rates and 12% direct contribution at the start. If you max out your 401k you'll make contribute no less than $53k on a conservative Captain salary at that pay rate.

Yes you'll be junior and on reserve but the movement is and should remain fast for awhile as potential upgrades leave. Until they get serious about improving QOL (schedule flexibility, vacation program, etc) you can expect many of the young FO's that would bump you down will leave before getting the chance. If you live in base, especially a junior base, you can make a decent go at is as a junior Captain making good money and piling up retirement. Get yourself into the training dept or become an LCA and you have a golden ticket. I know a several who have returned or came in DE and its alway been honored. If you left on good terms and have continued so at you current airline they should most certainly welcome you back.