I have a Soma rear hub that is probably a year or so old and is certainly a rebranded Joytech (the bearing is labeled such). The bearings themselves are already quite notchy feeling when I spin the axle in my fingers but perhaps this is common with lowend cartridge hubs, I have no other experience.
When I got my wheel it was the only affordable, prebuild fixed hub wheel available to me.
I definately wouldn't pay more for them than Formulas (unless it is the pretty colours you are after, I guess).