>While I agree with you, the overhead is not enough to worry about IMO. Unless the data is fixed length, I always use nvarchar for strings.

I am pulling from BOL:

Use char when the data values in a column are expected to be consistently close to the same size.

Use varchar when the data values in a column are expected to vary considerably in size.

If is your experience that there is not much of a performance difference? Also, why nvarchar? Is Unicode that popular, or due to the fact the SET ANSI_PADDING is always ON?