Initial reaction: tricky, however with practice, this tool works extremely well. For (relatively) quick key changes between songs to accommodate the singer's key, you are able to work in familiar fretboard areas. An added bonus is a change of key may enhance the sonic quality.
Pro's: adds musical benefits...works fine with lap steels fitted with Certano benders too.
Cons: Pricey and a bit fiddly when first used. There is a learning-curve due to solid construction and adapting to playing.
If lost, I'd order a new one immediately.