It's still possible to get DE blades with bad edges. It's not common, but from my time hanging out at B&B it doesn't seem rare, either.

In my personal experience, a microscope is most helpful for identifying a bad edge. An edge that looks good under magnification may or may not shave well. I used my microscope constantly for several months, but I haven't picked it up since Christmas. It taught me a lot, and now I can get the same information from other tests.

Just my 2 cents,
Josh