I don�t have a 45/70 but I have its cousin the 450 Marlin�
I believe they are both fantastic rounds�
If you keep in mind they are what they are� if you need something more powerful than either can provide� move up to one of the DG 458� (Win, Lott�)don't try to push either one harder.
That seems to be the main bone of contention.
IMO