Get a Sub2000 or wait and see if the JRC or Nano carbine come out with Beretta 92 mags.
Planning to move to a freer state and may want a trunk gun.

I am pondering the same thing.  I love  my CX4 and have many Beretta 92 mags (and a 92A1).  The only thing the Sub2000 has that is unique is the ability to fold.  But, they are hard to find and cost as much as CX4 these days.  I have been thinking another CX4 makes more sense all around, as I would put different optic (variable powered scope) on the second CX4.

My problem is I like having a wide variety of guns, and enjoy them all.  But the cost and storage of increased varieties of magazines it starting to make me hesitate.

I wouldn't get the sub.