NPM vs VMAN

Our Solarwinds NPM interface licenses are about to meet the subscribed 2000 interface license limit.
The current occupied interface licenses include the virtual infrastructure VM interfaces as well.

Now I would like to know that If we go for VMAN tool instead of upgrading the NPM, for managing/monitoring of virtual infrastructure separately and not through NPM.
would it be wise and what kind of additional information I can get through VMAN which was not possible through NPM?

Looking forward a sincere advise.