Take whichever calls first for a class date....

Then see how it goes. When the second one calls, think about it, or defer if you can for a bit so you can really think about it.

I would chose United any day over Delta. I do not care for the attitude that Delta has displayed towards corporate Pilots.

After 4 airlines I'd say culture matters and I would commute to a good culture.
Just don't chase money.
I'd go for Delta.
Good luck with your decision!

After 8 airlines I would say they are pretty much all the same. Go with the first one who calls. Seniority is everything. If two call at the same time, dont commute.

That's funny, I never even think about corporate pilots.

Shack! It really only comes down to this. It's just a job, put your family, your life and anything other than the very bottom of Maslow's pyramid ahead of this.

Delta! It's the only airline where I haven't had to hide my loathing for corporate pilots.

The OP said it - it's a no brainer.

If only one calls you the choice is pretty easy.

What if UA hires him and a month later he has a DL class? Or two months later? Six months? A year? At some point jumping to DL makes sense and the longer the delay waiting for DL's class the tougher the decision gets to make the jump.

There are people in this situation - already hired by their #2 choice and have job offers from #1. Every airline has hired guys from, or lost guys to, other airlines. And some have probably made the decision to stay with #2 because of the lag to getting on #1's seniority list.

Fixed it for you