My son has a Marlin in 45/70. I don't recall which model - if there is more than one.
I've shot it enough to have an opinion. These are the down sides.
It does kick quite a bit.
If wasn't really scope friendly. The scope sat rather high. He took it off - in part because of the next observation.
It has a trajectory like a mortar. That's ok for a range where you know the distance to the target. Not so good if you are hunting in an open area. I don't think you need a scope at those ranges.
The ammunition is a bit on the expensive side.