The point is, though, that todays high-speed logic IC's can take you by surprise.

It seems that the IC technology improves so fast that to catch all you must pay an arm and a leg for a "sufficient" scope. I remember some years ago trying to find a problem and not seeing anything on the scope. I did a "manual timing analysis" on the circuit and realized that a .1 to 3 ns pulse could possibly exist erroneously at a given point. The available scope did not show diddelysquat, but a small capacitor to remove pulses less than the "real" one fixed the problem.

The morale of this story is that you have two options:
1) pay, pay and pay for a "luxury scope" and almost believe in what you see - or
2) buy an affordable scope and be suspicious of everything you see.

Erik