I've cut my non AC 71 and never regreted it one bit, but that truck was not stock nor was it planned to be stock.
Now that I have the '72 going, I would never cut the dash! Its about 85% stock all over and I think it would ruin the look if I installed a later model stereo in it. I'm going with the aftermarket models that fit our trucks and work like the new stuff.
I think it all depends on your intended use. If your going for stock or may go for stock at some point, DON'T cut a perfectly good dash. But if your going for custom and didnt really prefer the stock setups, cut away....
My 2 cents