In our Sprucetuck game, a few of the players struggled with:
Some of the players are used to D&D 4 where planning can be a crucial component of play. The idea that the person who thinks of a plan has to make the roll was a problem for them. We played mostly rules as written but there was resistance and at least one of the players reacted with astonishment at the idea. This was the only rule that got this reaction. Everything else went smooth, even scripting which 2 of the players had minimum to no experience with.
As a GM, my biggest mistake (I think) in our games involved this rule. There was a moment where a player wanted to climb a wall into enemy territory. Most of the other players wanted him to wait to discuss the optimal tactical plan. The climbing player paused in frustration to hear them out and eventually decided to climb the wall anyway. My mistake was I should have had the climbing player roll immediately since they announced the action rather than let the other players talk them down. In the end it worked out fine but this was one of the few bumps in the road we hit.
Best,
John