After 5...Bd7 6. Be2 the only move anyone in their right mind plays is Nge7, and while I would not call black's position equal it's certainly the main line after move 5, rather than this Qb6 f6 silliness...
The above post does show that 5...Bd7 does not mesh with Qb6 systems, but to make a broader conclusion about 5...Bd7 you need to do much much more than that
It is not Qb6 and f6, it is either or.
For a while the hype train favored 5...Bd7 and 6...f6, but White just ignored it and castles.
6...Nge7 can be played first, but what then after 7...Nf5? (7...Ng6, going for e5, is dubious and White should answer with storming the h-pawn).
Black has to go at White's center somehow. If you are not going to play f6 or Qb6, what are you doing? Sacrifice a knight?
Oh I probably should also note that for the advanced variation GM Pert only covers the Bd7 line as opposed to the more popular Qb6.
Not knowing much abot the French yet, what is the current status of Bd7 and Qb6? Are both playable? Depending on the answer it could be interesting to check what the different DVD's recommend.
Btw, I forgot to say that I did watch parts of a chessbase DVD on the French by Ari Ziegler where he recommended Bd7. That DVD is old now.
Back in the 90s, both were considered playable. Now, 4...Bd7 and 5...Bd7 are significantly weaker than the ...Qb6/...Nc6 lines.
After 1.e4 e6 2.d4 d5 3.e5 c5 4.c3, if Black is going to play the ...Qb6 lines, I recommend 4...Qb6 and 5...Nc6, not the other way around. Reason being is that 4...Qb6 avoids the annoying 5.Be3 sideline (b2 hangs and this time it can be taken).
Now, the problem with 5...Bd7. I shall compare 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Qb6 5.Nf3 Nc6 to 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Bd7. The first diagram below is Qb6!, the second is Bd7?!
Is 6..Nge7 not playable anymore? As I understand it white has two main replies to it. 7. 0-0 and 7. Na3. Against both moves Blacks main plan is to put the knight on f5, play Qb6, Na5, and Bb5 to trade off the light square bishop. When g4 is played the knight retreats to e7 and soon black will try a pawn sac h5 to try to get the f5 square back for his knight. If white castles then black will castle long and try to attack whites castled position. I do think Qb6 is probably the better move theoretically but I kind of like the complications in the Bd7 line.