With a wiped cam, it's mostly just one lobe that gets wiped. This results in an engine running like it's missing a cylinder.
If the wear gets big enough there will also be lifter ticking-noise which will become louder every time the engine is run.

Power down with a smooth running engine could be a lot of things.
Most likely causes;
Vacuum leak, ignition timing issues, bad carb tune, wrongly installed (or not degreed) cam, worn piston rings.

A vacuum gauge can tell a whole lot more of where to look for issues.