Picked up a cheap wireless borescope off Amazon last fall and it caught a cracked baffle in a Cessna 172 that I would have missed with just a mirror. That one find stopped an engine tear-down later that would have cost the owner around 7k. Worth every cent for the peace of mind alone. Has anyone else had a cheap tool end up being a lifesaver on an inspection?
How long did it take you to get used to steering that thing around inside the engine? I borrowed one once and spent half the time fighting the cable and the other half trying to figure out which way was up on the screen.