I’ve got a Callaham, US and MIM Strat bridges. Practically no tonal difference I notice between the two Fender bridges, they’re on different guitars and whatever differences there are between them could be any one of the differences. Regardless, the Callaham is stellar, just holding the thing you get the idea you bought something someone put effort into. Swapping it out with the Fender introduced some top end clarity, not like turning the treble up, but an overall better presence and a sharper attack.
Definitely won’t be my last Callaham.