If you can
really only have one (and why do you need
TWO kidneys anyway ?) I'd opt for the 24 Panoptic.
Wider, 'flatter', FoVs in yer dob and it barlows beautifully. I use mine in Binoviewers in my Mak, my Dob and my f6.3 refractor.
BV'd, barlowed, straight-up - they perform beautifully in everything.
Its verging on an inappropriate relationship!
I also have the 13 Nagler and it too, is an excellent mid-high power ep and I love it to pieces as well.

It's just a little less versatile IMHO.