What is the difference between Apex Data Loader and Import Wizard as far as record...

Apex Data Loader, Loading of a record fails if even one column/field has invalid data in it. Import Wizard, Inconsistent behavior. Sometimes the field with invalid data is not loaded but the remaining record gets loaded as mentioned above when text value was provided in a field of type number but the field was not a compulsorily required field. The record loading fails if this field is made a compulsorily required field.