I still use a basic timing light for tune-ups (most guys think I'm nuts for it). A customer's truck wouldn't fire after the shop tried all the new diagnostic gear. I hooked up my light, made a few adjustments by feel, and it cranked right over. Felt pretty good to solve it with such a simple tool. (Guess sometimes the old methods just work, huh?)
Spending weekends under the hood with a timing light feels real. All these new scan tools just distance you from the machine.