Shedlon Dingwall alwats says it takes you ten minutes... ...but he's the (great) guy selling the things. I tried several multi-scales, also a four string Ibanez, and you get used to it very fast. The only more difficult thing - and Sheldon admits that - are the very high positions.
I love the D-Bird, a fanned fret Thunderbird, developed with my Dutch bass friend Rob van der Loo of Epica.