I'm a pretty big FM fan but FM15 is probably the worst football manager/championship manager in years.
There are a couple of things that they may be able to fix in the next patch like the ridiculously high number of injuries and the awful set-pieces, but there are a few thinks stuck until next year:
Layout is awful
Too many interviews/press conferences
Scouting takes too long
The match engine is poor, heavily based on wingers/crosses.
I would recommend not buying it, and getting fm14 at a reduced price but as NYCFC are in this game , then I will recommend using Classic mode (a quicker, compacter mode) as it is much faster and limits the damage. less press, easier scouting etc.