digital xover and driver correction

[mrkahn]

I am wondering if anyone could shed some light on how digital xovers affect signals.
To be specific, it seems that one can do a lot of correcting and tweaking to a drivers response with a digital xover like a dcx2496. You can go bananas and make modifications to your xover design and flatten out response etc but does all this tweaking degrade the signal (music)?
Does one still need to select a driver best suited to the task you intend it for or with digital correction you are able to make a driver behave more to your needs? Are there trade offs?
Basically what I am trying to understand is if you flatten out a hump or a dip by +-2db or +-20db digitally is there any difference?
I have no idea....