Using Zoho Forms vs Zoho Survey

Using Zoho Forms vs Zoho Survey

Hello - I'm looking for advice on whether to use Zoho Survey or Zoho Forms for our small non-profit. We have a Zoho One subscription, so have access to both. 

The main use case at the moment is application forms for our professional development programs. We've used Zoho Survey in the past, but I'm wondering whether there are any benefits to switching to Forms. Here's the key features we need (not in any particular order):
  1. Reponses sync with Zoho CRM (ability to choose which fields to sync, plus ability to attach PDF of all responses to the contact record)
  2. Respondents can save an incomplete application and return to it later
  3. Scoring / weighting of particular questions in the backend
  4. Reporting on all submissions (i.e. 67% of people gave answer X to Q2, 33% gave answer Y)
  5. Document merge - create PDFs that can be emailed to respondents AND other contacts (i.e. internal staff) 
  6. Trigger emails with conditions - i.e. send X email to the respondent if they answer this question this way, if not send them Y email
Given all these features, which option would be better for us? I can't seem to find any clear explanation of the difference between Forms and Survey and the use cases for each, so any insights gratefully accepted!