[BACKCHECK!!!]

There are many ways to gauge compete level. Some of which are more subjective than others.

For exmple:
How often does a player continue to move his feet when he's pinned against the boards?
Does he fight through checks?
How fast does he skate to the bench on a shift change?
Does he dig in his skates to hold his ground in front of the crease? With or without cross checks?
Does he dig at pucks after the other goalie makes the save?
When the puck goes into the corner, does he try to win the race and take the hit, or lose the race and hit the other guy?
If he gets stripped of the puck, does he usually stop hard, turn around and chase it down, or does he wheel around, or does he go for a shift change?
How often do you see him at max speed?
If he can hit max speed in 5 strides (for example) how often do you see him actually do that?

Most of these can be broken down into "Always/Sometimes/Never", or something close to that. It's not much more subjective than pretty much any of the other things scouts look at.