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  • Dustin Waybright thinks this is interesting:

When you need to store character strings, if they will likely vary in length, use the NVARCHAR or VARCHAR data types rather than the fixed NCHAR or CHAR. If the column value might be updated often, and especially if it is short, using the fixed length can prevent excessive row movement.

From

Cover of Training Kit (Exam 70-461): Querying Microsoft® SQL Server® 2012

Note

CHAR and NCHAR require data to be the same length.