Does the War Powers Act gives a check against Presidential overreach in military acts?

The War Powers Act does provide a check against
presidential overreach, but it is not an especially strong
one. 

No President has ever acknowledged that the War
Powers Act is actually constitutional.  Therefore, it is not at all clear that the act
could ever be used to force an end to a military action taken by the president.  This
weakens the effectiveness of the act
significantly.

However, the act does provide a check.  It
forces the President to at least justify his (or someday her) actions to the people. 
This allows public opinion to have a great effect on whether the President's actions are
allowed to stand. 

So, the War Powers Act provides a check
because it forces the President to expose his actions to somewhat of a public
referendum.  It does so by making the President at least consult Congress over his
actions.