As I said, I do not own or use Plasticity.

But if I must ,I will opt to purchase Plasticity instead of upgrading to MOI3D ver 5.0.

I much prefer the user interface of MOI3D over Plasticity. I find Plasticity's UI confusing and awkward.

But I do like how Plasticity uses the same shortcuts as Blender. I wish more apps would adopt this.

Plasticity does not have a user forum like MOI3d, It has a discord channel. I do not like discord. I prefer user forums.

Despite Plasticity being the newer kid on the block there are much more easy to follow how-to's, tutorials and tips on youtube.
Many are done at a near pro level with clear narration.

Sadly MOI3D does not have as many users willing to share their tips and techniques on youtube like Plasticity.

For some reason which escapes me, Plasticity appears to be favored for automotive modeling.

If ALL the above was equal, I would be a MOI3D user for life as I find MOI3D a much more pleasant experience.
MOI3D is fantastic, but lacks the user support and tutorials like Plasticity.

Cheers and take care...

Ken