What happened to User Fields in CSF?
Some of them are still there in the Business Class (a file with functions built into it) none of them are on the forms.
Some forms do have tabs for user fields, there are no fields there and the fields need to be added using Configuration Console.
Attributes which have always been user fields on steroids, also go away in CSF. Using Configuration Console any kind of custom field can be added.
In conclusion, user fields are not gone, you can still have as many as you would like, they just need to be added to the forms and sometimes to the business class using Configuration Console. Keep in mind that the system updates every 3rd Saturday so it is best to add only those that you really need.