After 4.Bd3, black is asking for trouble on the light squares.
Caro-Kann Advance variation with 6 f6

One of my very first games when I returned to chess in 2008 was against this exact variation. This game was played between an unrated player and me as white (a 1228 player at the time). There were obvious errors on both sides.

What do you think about it?
If you want to start a game off by defending weak light squares around your king, then by all means play it.

What do you think about it?