Without question, I'd do the JCAP.
Honestly, other than a nice chat, my NCS appointment was very unremarkable. I had my crap in order. No changes. Didn't have anything they didn't need. Wasn't missing anything they did need. So I'd be fine with either service. Honestly, just go with whichever you want. There is no bad choice!!!
To confirm, if I do NDRS, the order of operations is:
1. Gather supporting evidence and complete relevant sections of passport application.
2. Book and pay for NDRS+JCAP appointment.
3. Submit and pay for online citizenship application when appointment's within 10 days.
4. Give biometrics
5. Attend NDRS+JCAP appointment.
Then I just wait until I'm invited to schedule a citizenship ceremony. Yes?
I did an NCS only appointment and applied for my passport after. I filled out the application and sent it off immediately after the ceremony. I received an invite for an interview 2 days later, had the interview a few days after that, and my passport the following day. I think it took a total of 8 days to get. So, if you really want to go to an NCS appointment and can't get a JCAP appointment at the same time, it might be a viable option to send it off after.
Oh, that's quick turnaround. That wasn't expedited, or anything? Just standard processing time? (Not that I'm in a rush... we don't have any trips planned, or anything!)