I often have to put data into a particular Data Model for our clients and then get an error that the string is too long to fit in the field where I've mapped it. This error often occurs after someof the data has been appended! It would be better if the mapping tool either displayed the column width along with the "(Text)" - e.g. (Text- 20) or raised a flag to indicate that the input field is longer than the target field. You could then either proceed or come up with a solution before it does only some of the features.