do you use effective M?

[Dr1Gonzo]

In case you don't know, effective M refers to your actual M and the number of players on your table.
It is calculated by:

M x (Number of players on table/10)
Note: edited this to read 10 instead of full no. of players

So, you have an M of 10 on the final table but it is now 5 handed. Your effective M is therefore:
10 x 5/10 = 5

This is supposed to indicate how aggressive you should be but it effectively turns 3xBB raise situations into pushes.

Does anyone actually use this? I really only see it happening when there's 2 tables left in an MTT just before players reach the final table...and then on the final table itself.