I prefer the Cambridge Springs and intend to reach it via the Semi-Slav move order. This is a direct replacement for the Botvinnik variation, which I no longer trust. I think there are plenty of chances for White to go wrong in the CS.

I never felt that comfortable with the Moscow line, it always seemed that Black's position was hanging by a thread. Its pretty exciting though.

I played against it last Saturday and lost with White in 21 moves. Ho hum.

I reckon that beloww 2200 or so it's perfectly possible to generate winning chances on the Black side of the Exchange QGD with Nf3. You don't just have to sit there while the queenside pawns advance.

I have been pondering over the exact same question for a few days now.  For starters the Cambridge Srings approach allows white to play the Exchange QGD.  As white can't play the lines with Nge2 this isn't totally scary but I feel generating real winning chances against a white player who knows how to handle the Carlsbad structure is tricky.  Secondly, in both the Moscow and Cambridge Springs black often wins a pawn.  From the games that I have seen white has better chances of developing an initiative in the Cambridge Springs as black often wins the c3 pawn in exchange for the dark squared bishop and losing time with his queen.  In the Anti Moscow gambit the price for a pawn is the weakening of the black kingside and often the ineffective Bb7.  I feel more comfortable in the Anit Moscow than I ever did in the Cambridge Springs - although in the Cambridge Springs there are a few traps for the unwary!

Regarding Nimzo and Benoni they both unbalance things either minor pieces or pawn structure early on.  If I'm assuming you mean to only play the Benoni after Nf3 than I'd say the Semi Slav produces the sharpest positions - but also a number of duller positions e.g. exchange Slav etc.