Damned handy I say.
The issue with working with Windows is it's language based, so if you want to use an 'E' with an accent or acute, it would be near impossible unless you could copy or paste one. The character map makes it possible to find lots of characterisations from other languages quickly and in the same font as you're using without taking all day about it.
As far as the other symbols are concerned, it's good for them too. Much quicker than trying to find stuff by iterating through key strokes.