Moderate, only because of a few of the online trophies, like the Mother Goose one, which requires a little bit of luck to get. i was lucky enough to have someone drop a sister about 3 feet from the vent for me.
A few tips for the MP without boosting:
* always play a team game. the winning team gets 200 Adam, the losing team gets 150. I prefer Capture the Sister.
* if you suck at killing people (like me), focus on looking for Adam vials, hacking machines, and taking photos. Most of the time people will make a mad dash to kill others or to get the game objective (like capturing the sister), leaving you to root around at the start. hug the walls and you will discover clusters of adam vials. The best i did in one game was 19 vials.
I didn't boost, and here's my breakdown:
97,000 needed for lvl40
wins 43, losses 127 (170 games)
916 kills (average of 5 kills a match), 689 assists
1264 vials of Adam
12,425 in points from the trials
trust me, it is not that tough. And for those people who complain that MP is dead? if you don't get right in to a match within a minute, exit out and go right back in to the same game type. most of the time you will get put into a partially-completed match.