I agree. A light is the only way to go for any accurate assessment and adjustment of your timing.
And if you're going to invest in a timing light, get one with a degree wheel. All a timing light without a wheel is for, is to set your initial timing at idle and that is it. With a degree wheel, you can recurve your timing advance weights, check and verify vac advance, see what you're getting for full advance with both mechanical and vacuum advance all in etc. If you're timing is off and missing the mark or timing tab, you can even find out how far out it is before you start making adjustments and know how far you retarded or advanced it.