You're also better off just inserting the 'No Comments Provided' when you create the record instead of going back and updating the record later.
True, but even better would be to leave NULL in the row, and return 'No Comments Provided' from a view or even a computed column, rather than wasting space by storing 'No Comments Provided' in row after row. This becomes much more true if later you decide to change the literal used for NULL comments to some other string; if it's stored, you have to physically update every row, but if it's derived in one place, you simple change it in that one place.
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial: "If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them."