I notice it on the edges of the fuselage especially at the belly against the sky, the rear flaps against the sky. Also the titles .. .the jaggies are a bit longer than normal sharpening makes them look. I tend to look at that as a sign I have gone over. But, don;t take my word as the final

If you note my last thread, I am also not that good at spotting sharpness from time to time LOL. But I am getting a bit better at the oversharpening. I think it shows up as a harsh edge with longer (if that's a way to explain) jaggies. Most screens can't display ramps with such little data so on small images, edges can have a staircase effect. Depending on the angle of the edge and the contrast of the edge, the sharpness or averdoing of such can show up more or less readily.
my $0.02
Cheers!
Manny