Pros of multi-view:
- You can verify that each field is valid before letting the user proceed to the next field.
- You can press enter to go to the next field instead of tab which is nice because many users often press enter without thinking since that is what you need to press after filling out the last field.
Pros of single view:
For users, single view will appear as simpler. Simple always wins!
When users see a form with let's say 5 steps, they will automatically calculate that the form will take 5 times as long to fill out as a form with only one step. They have no way of knowing that each step is only one short field.
Multi-view sign in will seem more complicated to a user since it is an entire extra step.
By showing everything on one screen, users right away see everything they will need to fill out. Users like to be in the know :)
It is easier for users to correct previous field when they can just click on an above field, instead of needing to go back a whole page.
Many users will be using touch devices. On these devices, many users prefer just tapping on the next field instead of using tab or enter.