In the Caro-Kann Panov-Botvinnik Attack 5... e6 6. Nf3, what are the differences between 6... Be7 and 6... Bb4 ? Which one is more solid and quiet? In the Caro-Kann Panov-Botvinnik Attack 5... e6 6. Nf3, I am hesitating between 6... Be7 and 6... Bb4

  [StartPly "11"]

  [FEN ""]
  1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 e6 6. Nf3 Be7 (6... Bb4)


I would like to know all the differences between these two moves.

Which one of these two moves tends to lead on average to the most solid, positional, boring, strategic, slow and quiet positions?
As surprising as it sounds, 6...Bb4 is probably going to lead to the quieter game.  The reason is that with the bishop on b4, pieces will get traded off on c3. 

As an example, the game Najdorf-Portisch 1-0, from 1962 shows some of these ideas.  Although the game begins as a 1. d4 game, the position transposes directly to the Panov Botvinnik.

[FEN ""]
[Event "Varna"]
[Site "Varna"]
[Date "1962"]
[EventDate "?"]
[Round "3"]
[Result "1-0"]
[White "Miguel Najdorf"]
[Black "Lajos Portisch"]
[ECO "B14"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "43"]

1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.cxd5 Nxd5 6.e3 cxd4
7.exd4 Bb4 8.Qc2 Nc6 9.Bd3 Nxc3 10.bxc3 Nxd4 11.Nxd4 Qxd4
12.Bb5+ Ke7 13.O-O Qxc3 14.Qe2 Bd6 15.Bb2 Qa5 16.Rfd1 Rd8
17.Qh5 f6 18.Qxh7 Kf7 19.Be2 Qg5 20.Bc1 Bxh2+ 21.Kxh2 Qe5+
22.f4 1-0