to be honest i cant come up with anything better then exchange sacrifice on c4, i know its more of a strategic idea you ask for, but thats all i can come up with to free blacks position, even though i have the feeling its totally incorrect.
i would evaluate it as winnning for white, unless the exchange sacrifice works.
I think white can decide between a kingside attack and a winning endgame against a bad piece, unless black can free himself with the exchange sacrifice.
This is an interesting, non-book position, which (rather obviously) has emerged from a Steinitz French.
It's black's turn to move. The questions are two:
1. How do you evaluate this position? Plans for both sides are welcome.
2. What should be Black's best move?
Feel free to use any sort of aid available, including GM advice, engines, strategy books, whatever.
I will wait for as many answers as possible before replying back/ expressing my own opinion.
Regards.