Di Maria, all things considered, wouldn't look as bad if you'd not well overpaid for him at the start. Had you paid somewhere around what your now reported to soon be receiving back; the loss 1 year in wouldn't look half as bad.
To a wider point on Di Maria, sometimes great players, what ever reason, just don't fit at certain clubs and in certain leagues. We had one in Morientes. Fantastic footballer. Great fro Real, Monaco and Spain. Came to England and Liverpool and nothing he did went for him. Went back to Spain, and it was like he was never away. It just is what it is.