The total number of source points could be similar, depending on the distance between your source points on the volume grid. Overall, the surface/unconstrained and volume source models would provide very similar information, but I find volume results more difficult to review and to work with in general. Having the data projected on the cortical surface makes the visualization easier.
If you are satisfied with the current results, there is no need to do anything else.
Unless you want to try it out just out of curiosity... you might find the volume displays in the MRI easier to understand or better suited for your study.
https://neuroimage.usc.edu/brainstorm/Tutorials/TutVolSource