IIRC the CX line was their better or best models while the BX and anything with "Extra" on it was kind of their middle and budget model lines. While the "Americas" were their sort of a late 80's special that had an option for having aluminum cogs when you buy the "Leggera" version of it.
Had good luck so far with Reginas. They seem to generally have better mechanical tolerances than their French equivalents, but do sometimes suffer from internal knock as the two halves of the bodies can hit each other while spinning if there is just a slight deviation from their design during manufacturing. But if you get one that's built good, they can be the quietest and smoothest FWs you can put on a bike and despite some clearance problems with getting a FW remover on with the axle lock nuts in place on some hubs, I really like the really positive engagement with the splined body and the FW remover on most of their FWs.
Only thing I do question about their FWs is their decision to thread the middle cog on the CX models. These middle cogs are almost impossible to take off as they are most used on the FW, thus gets really tight on the body after some time. Why they didn't just thread the smallest cogs (as most other manufacturers did) is puzzling, as that would have been adequate to do the job of retaining the cogs on the FWs.

Chombi