Headers get a bad rap because most people overtighten the fasteners and warp the flanges, or use crappy gaskets that blow out. I've installed headers on dang near every V8 vehicle I've ever owned, and have not had the problems everyone associates with headers.
I will add this though... changing spark plugs on a SBC with headers could be a new Olympic Sport. Get's a little tight, but if you take your time and know a few tricks, it gets easier over time.
Gary