Google forms have the following features which I believe make it the best:
1. Can be customised according to the requirement of administrator.
2. User-Friendly and is available free of cost.
3. Previously available form templates.
4. Simple and presentable Interface.
5. Can be accessed through mobile phones (Hand) as well.
6.Basic Analytic tools available such as Summary, Graphical Representation, etc.
7. Data spreadsheet is easily downloadable and can be edited at any point of time.
8. Also, the feature of closed forms does not allow further entries to the form.
Some of the limitations of Google Forms are as follows:
1. Sub-questions cannot be made. i.e. inter-related questions cannot be formed.
2. Privacy can still be questioned on google forms.
3. Money transactions through these forms cannot be done. Another link is to be added to make the transaction complete.
4. Limited space available to create forms.
5. Multiple features like change in font , or more designs of background needs to be added to google forms. More professional template is required
It works perfect for collection of data and surveys.
I use it for unprofessional purposes as well and it works perfectly without adding cost to its uses.
Also, it helps in manipulating the data properly.