Sometimes you do get extra information on the license, other times not - or the license hasn't survived at all.
You can get occupations, marital status, occasionally the brides father's name. Sometimes when you can't find the marriage, you can find the marriage license!
The great benefit was pre-1754, when the PRs often only gives names:
1713 7 Jul Francis Button & Judith Coles marryd at Towcester by Lic
and the license sometimes gives more (and sometimes vital) information:
Francis Button of Abthorpe husbandman, widower & Judith Coles of Abthorpe widow
Bond Francis Button & Francis Linnell of Towcester innkeeper 5 Jul 1713
Very often, there's not much extra, if anything, but it's always good to see if they're still around.