Bought a cheap set of lens spanners online for $140, thought they were garbage when the tips kept slipping on a stuck retaining ring. Left them in a drawer for two months, then dug them out during an emergency repair on an old Pentax and they gripped perfectly after I filed the tips a bit. Now they're my go-to for stubborn rings, go figure. Anybody else had a tool they hated at first then ended up loving after a little tweak?