What's the relative percentage of the junior CA at Spirit? 60%? 65%

That's means they'd have to grow by approx 50-60% for a guy hired today to upgrade by year X. That's the reality, and downside, of getting hired later in the hiring cycle.

Looking at APC's NK page it looks like that growth will be achieved in 2021-2023 if NK maintains it's current growth rate.

You need to write future resumes, projecting on a yearly or two year cycle, as if you'd made different career choices. Be realistic on your estimates and projections and the choice might become more obvious.

The goal isn't what's the coolest or best job right now but what path gives you the best chance of reaching your final goal first. I took big pay cuts, and jobs a step down in status, while focusing on the long term goal. If I'd stayed with the 'better' job(a lot more pay but a lot less flying) it would have taken me another 2-3 years to have a competitive resume.