[Leica] Query re B&W photography in digital

[tomschofield at comcast.net (Tom Schofield)]

Here is a questions for all of you artists of the monochrome medium  
who have made the digital transition --
a question which I have not found the answer to elsewhere --

I understand that you can duplicate the effect of yellow-red-orange- 
green contrast filters by manipulating curves in PS or other  
software, but my question is whether there remains any advantage to  
using the glass filters on the lens in the first place if you intend  
to make a monochrome image?

For example, in addition to changing the relative values of the sky  
or foliage or skin with filters, haze penetration is another benefit  
to using a red, orange, or to lesser extent, yellow, filter -- i.e.  
do you still get haze penetration effects by dialing down the blue  
channel?

Thanks for you insight,

Tom Schofield