[Sorenant]

As a GM I'd be happier if you spent those points in some form so I can better plan what to do next.
If the characters went from X points to X+50 points, I'd prepare challenges accordingly but if one of he players decides to stay behind, that's yet another thing for me to account for. Better GMs might breeze through this sort of preparation but unfortunately I'm not that good, so I'd be happier if they spent those points even if for things like Luck, Serendipity, Gizmo, Common Sense and Intuition.
Fortunately I never faced such problem, players tends to always want something more for their characters.