Len,
Your poll is, for me, is impossible to respond to SPECIFICALLY

as you request.
Starting all over again with no LR rifle I would go again with the 270 AM. And now knowing the quality/shootability of the 169.5 WC bullet I would have bought a lifetime supply of them. However, I didn't so I have to build my own bullets.
To answer the "my next cartridge" will be. No sense in going a next step. Why not take the Looooooonnnnnggg stride. Neither of my choices are in the poll....... Mostly just cause I can.

I'm not gonna become extinct with my dreams still in me.............